C I V I L I Z A T I O N    A D V A N C E S
   Cross Reference


<- = prerequisites, listed in reverse chronological order
-> = successors, listed in forward chronological order


ADVANCES
--------

Alphabet-> Writing, MapMaking, Code of Laws, Mathematics, 
 Diplomat, Library, Trireme, Lighthouse, Courthouse, 
 Literacy, Monarchy, Trade, Catapult, Astronomy, 
 Great Library, Republic, Philosophy, Feudalism, 
 Caravan, Copernicus, Navigation, Banking, Medicine, 
 Religion, Democracy, University, Chivalry, 
 Invention, Sail, Magellan, Physics, Bank, 
 Shakespeare, Cathedral, J.S. Bach, Michelangelo, 
 Chemistry, University (Imp), Theory of Gravity, 
 Knight, Gunpowder, Magnetism, Steam Engine, 
 Isaac Newton, Atomic Theory, Explosives, Musketeer, 
 Metallurgy, Frigate, Railroad, Ironclad, 
 Conscription, Cannon, Electricity, Darwin's Voyage, 
 Industrialization, Rifleman, Electronics, Transport, 
 Factory, Women's Suffrage, Steel, Corporation, 
 Communism, Hydro Plant, Hoover Dam, Computers, 
 Battleship, Refining, Genetic Eng., United Nations, 
 SETI Program, Power Plant, Combustion, 
 Cure for Cancer, Automobile, Cruiser, Flight, Armor, 
 Mass Production, Fighter, Advanced Flight, 
 Labor Union, Submarine, Mass Transit, Recycling, 
 Nuclear Fission, Bomber, Carrier, Rocketry, 
 Mech Infantry, Recycling Center, Manhattan Project, 
 Nuclear Power, Nuclear Unit, Space Flight, 
 Nuclear Plant, SS Structure, Apollo Program, 
 Plastic, SS Component, Superconductor, Robotics, 
 Fusion Power, SDI Defence, Artillery, Mfg Plant, 
 SS Module

Bronze Working    -> Iron Working, Currency, Legion, Marketplace, Trade, 
 Construction, Caravan, Aqueduct, Colosseum, 
 Fortress, Engineering, Bridge Building, Banking, 
 Medicine, Invention, Bank, Shakespeare, Chemistry, 
 Gunpowder, Steam Engine, Explosives, Musketeer, 
 Metallurgy, Railroad, Ironclad, Conscription, 
 Cannon, Electricity, Darwin's Voyage, 
 Industrialization, Rifleman, Electronics, Transport, 
 Factory, Women's Suffrage, Steel, Corporation, 
 Communism, Hydro Plant, Hoover Dam, Computers, 
 Battleship, Refining, Genetic Eng., United Nations, 
 SETI Program, Power Plant, Combustion, 
 Cure for Cancer, Automobile, Cruiser, Flight, Armor, 
 Mass Production, Fighter, Advanced Flight, 
 Labor Union, Submarine, Mass Transit, Recycling, 
 Nuclear Fission, Bomber, Carrier, Rocketry, 
 Mech Infantry, Recycling Center, Manhattan Project, 
 Nuclear Power, Nuclear Unit, Space Flight, 
 Nuclear Plant, SS Structure, Apollo Program, 
 Plastic, SS Component, Superconductor, Robotics, 
 Fusion Power, SDI Defence, Artillery, Mfg Plant, 
 SS Module

Ceremonial Burial -> Temple, Mysticism, Monarchy, Oracle, Astronomy, 
 Philosophy, Feudalism, Copernicus, Navigation, 
 Medicine, Religion, Democracy, University, Chivalry, 
 Sail, Magellan, Physics, Shakespeare, Cathedral, 
 J.S. Bach, Michelangelo, Chemistry, 
 University (Imp), Theory of Gravity, Knight, 
 Magnetism, Steam Engine, Isaac Newton, 
 Atomic Theory, Explosives, Metallurgy, Frigate, 
 Railroad, Ironclad, Conscription, Cannon, 
 Electricity, Darwin's Voyage, Industrialization, 
 Rifleman, Electronics, Transport, Factory, 
 Women's Suffrage, Steel, Corporation, Communism, 
 Hydro Plant, Hoover Dam, Computers, Battleship, 
 Refining, Genetic Eng., United Nations, 
 SETI Program, Power Plant, Combustion, 
 Cure for Cancer, Automobile, Cruiser, Flight, Armor, 
 Mass Production, Fighter, Advanced Flight, 
 Labor Union, Submarine, Mass Transit, Recycling, 
 Nuclear Fission, Bomber, Carrier, Rocketry, 
 Mech Infantry, Recycling Center, Manhattan Project, 
 Nuclear Power, Nuclear Unit, Space Flight, 
 Nuclear Plant, SS Structure, Apollo Program, 
 Plastic, SS Component, Superconductor, Robotics, 
 Fusion Power, SDI Defence, Artillery, Mfg Plant, 
 SS Module

Masonry -> Palace, City Wall, Pyramids, Great Wall, 
 Mathematics, Construction, Catapult, Astronomy, 
 Feudalism, Aqueduct, Colosseum, Fortress, 
 Engineering, Bridge Building, Copernicus, 
 Navigation, University, Chivalry, Invention, Sail, 
 Magellan, Physics, Chemistry, University (Imp), 
 Theory of Gravity, Knight, Gunpowder, Magnetism, 
 Steam Engine, Isaac Newton, Atomic Theory, 
 Explosives, Musketeer, Metallurgy, Frigate, 
 Railroad, Ironclad, Conscription, Cannon, 
 Electricity, Darwin's Voyage, Industrialization, 
 Rifleman, Electronics, Transport, Factory, 
 Women's Suffrage, Steel, Corporation, Communism, 
 Hydro Plant, Hoover Dam, Computers, Battleship, 
 Refining, Genetic Eng., United Nations, 
 SETI Program, Power Plant, Combustion, 
 Cure for Cancer, Automobile, Cruiser, Flight, Armor, 
 Mass Production, Fighter, Advanced Flight, 
 Labor Union, Submarine, Mass Transit, Recycling, 
 Nuclear Fission, Bomber, Carrier, Rocketry, 
 Mech Infantry, Recycling Center, Manhattan Project, 
 Nuclear Power, Nuclear Unit, Space Flight, 
 Nuclear Plant, SS Structure, Apollo Program, 
 Plastic, SS Component, Superconductor, Robotics, 
 Fusion Power, SDI Defence, Artillery, Mfg Plant, 
 SS Module

The Wheel    -> Chariot, Engineering, Invention, Gunpowder, 
 Steam Engine, Explosives, Musketeer, Metallurgy, 
 Railroad, Ironclad, Conscription, Cannon, 
 Electricity, Darwin's Voyage, Industrialization, 
 Rifleman, Electronics, Transport, Factory, 
 Women's Suffrage, Steel, Corporation, Communism, 
 Hydro Plant, Hoover Dam, Computers, Battleship, 
 Refining, Genetic Eng., United Nations, 
 SETI Program, Power Plant, Combustion, 
 Cure for Cancer, Automobile, Cruiser, Flight, Armor, 
 Mass Production, Fighter, Advanced Flight, 
 Labor Union, Submarine, Mass Transit, Recycling, 
 Nuclear Fission, Bomber, Carrier, Rocketry, 
 Mech Infantry, Recycling Center, Manhattan Project, 
 Nuclear Power, Nuclear Unit, Space Flight, 
 Nuclear Plant, SS Structure, Apollo Program, 
 Plastic, SS Component, Superconductor, Robotics, 
 Fusion Power, SDI Defence, Artillery, Mfg Plant, 
 SS Module

Horseback Riding  -> Cavalry, Chivalry, Knight

Pottery -> Granary, Hanging Garden

Map Making   -> Navigation, Sail, Magellan, Physics, Magnetism, 
 Steam Engine, Atomic Theory, Frigate, Railroad, 
 Ironclad, Electricity, Darwin's Voyage, 
 Industrialization, Electronics, Transport, Factory, 
 Women's Suffrage, Steel, Corporation, Communism, 
 Hydro Plant, Hoover Dam, Computers, Battleship, 
 Refining, Genetic Eng., United Nations, 
 SETI Program, Power Plant, Combustion, 
 Cure for Cancer, Automobile, Cruiser, Flight, Armor, 
 Mass Production, Fighter, Advanced Flight, 
 Labor Union, Submarine, Mass Transit, Recycling, 
 Nuclear Fission, Bomber, Carrier, Rocketry, 
 Mech Infantry, Recycling Center, Manhattan Project, 
 Nuclear Power, Nuclear Unit, Space Flight, 
 Nuclear Plant, SS Structure, Apollo Program, 
 Plastic, SS Component, Superconductor, Robotics, 
 Fusion Power, SDI Defence, Artillery, Mfg Plant, 
 SS Module

Writing <- Alphabet

   -> Diplomat, Library, Literacy, Great Library, 
 Republic, Philosophy, Banking, Medicine, Religion, 
 Democracy, University, Invention, Bank, Shakespeare, 
 Cathedral, J.S. Bach, Michelangelo, Chemistry, 
 University (Imp), Theory of Gravity, Gunpowder, 
 Steam Engine, Isaac Newton, Atomic Theory, 
 Explosives, Musketeer, Metallurgy, Railroad, 
 Ironclad, Conscription, Cannon, Electricity, 
 Darwin's Voyage, Industrialization, Rifleman, 
 Electronics, Transport, Factory, Women's Suffrage, 
 Steel, Corporation, Communism, Hydro Plant, 
 Hoover Dam, Computers, Battleship, Refining, 
 Genetic Eng., United Nations, SETI Program, 
 Power Plant, Combustion, Cure for Cancer, 
 Automobile, Cruiser, Flight, Armor, Mass Production, 
 Fighter, Advanced Flight, Labor Union, Submarine, 
 Mass Transit, Recycling, Nuclear Fission, Bomber, 
 Carrier, Rocketry, Mech Infantry, Recycling Center, 
 Manhattan Project, Nuclear Power, Nuclear Unit, 
 Space Flight, Nuclear Plant, SS Structure, 
 Apollo Program, Plastic, SS Component, 
 Superconductor, Robotics, Fusion Power, SDI Defence, 
 Artillery, Mfg Plant, SS Module

MapMaking    <- Alphabet

   -> Trireme, Lighthouse

Code of Laws <- Alphabet

   -> Courthouse, Literacy, Monarchy, Trade, 
 Great Library, Republic, Philosophy, Feudalism, 
 Caravan, Banking, Medicine, Religion, Democracy, 
 University, Chivalry, Invention, Bank, Shakespeare, 
 Cathedral, J.S. Bach, Michelangelo, Chemistry, 
 University (Imp), Theory of Gravity, Knight, 
 Gunpowder, Steam Engine, Isaac Newton, 
 Atomic Theory, Explosives, Musketeer, Metallurgy, 
 Railroad, Ironclad, Conscription, Cannon, 
 Electricity, Darwin's Voyage, Industrialization, 
 Rifleman, Electronics, Transport, Factory, 
 Women's Suffrage, Steel, Corporation, Communism, 
 Hydro Plant, Hoover Dam, Computers, Battleship, 
 Refining, Genetic Eng., United Nations, 
 SETI Program, Power Plant, Combustion, 
 Cure for Cancer, Automobile, Cruiser, Flight, Armor, 
 Mass Production, Fighter, Advanced Flight, 
 Labor Union, Submarine, Mass Transit, Recycling, 
 Nuclear Fission, Bomber, Carrier, Rocketry, 
 Mech Infantry, Recycling Center, Manhattan Project, 
 Nuclear Power, Nuclear Unit, Space Flight, 
 Nuclear Plant, SS Structure, Apollo Program, 
 Plastic, SS Component, Superconductor, Robotics, 
 Fusion Power, SDI Defence, Artillery, Mfg Plant, 
 SS Module

Iron Working <- Bronze Working

   -> Legion, Bridge Building, Gunpowder, Explosives, 
 Musketeer, Metallurgy, Railroad, Conscription, 
 Cannon, Electricity, Darwin's Voyage, 
 Industrialization, Rifleman, Electronics, Transport, 
 Factory, Women's Suffrage, Steel, Corporation, 
 Communism, Hydro Plant, Hoover Dam, Computers, 
 Battleship, Refining, Genetic Eng., United Nations, 
 SETI Program, Power Plant, Combustion, 
 Cure for Cancer, Automobile, Cruiser, Flight, Armor, 
 Mass Production, Fighter, Advanced Flight, 
 Labor Union, Submarine, Mass Transit, Recycling, 
 Nuclear Fission, Bomber, Carrier, Rocketry, 
 Mech Infantry, Recycling Center, Manhattan Project, 
 Nuclear Power, Nuclear Unit, Space Flight, 
 Nuclear Plant, SS Structure, Apollo Program, 
 Plastic, SS Component, Superconductor, Robotics, 
 Fusion Power, SDI Defence, Artillery, Mfg Plant, 
 SS Module

Currency<- Bronze Working

   -> Marketplace, Trade, Construction, Caravan, Aqueduct, 
 Colosseum, Fortress, Engineering, Bridge Building, 
 Banking, Medicine, Invention, Bank, Shakespeare, 
 Chemistry, Gunpowder, Steam Engine, Explosives, 
 Musketeer, Metallurgy, Railroad, Ironclad, 
 Conscription, Cannon, Electricity, Darwin's Voyage, 
 Industrialization, Rifleman, Electronics, Transport, 
 Factory, Women's Suffrage, Steel, Corporation, 
 Communism, Hydro Plant, Hoover Dam, Computers, 
 Battleship, Refining, Genetic Eng., United Nations, 
 SETI Program, Power Plant, Combustion, 
 Cure for Cancer, Automobile, Cruiser, Flight, Armor, 
 Mass Production, Fighter, Advanced Flight, 
 Labor Union, Submarine, Mass Transit, Recycling, 
 Nuclear Fission, Bomber, Carrier, Rocketry, 
 Mech Infantry, Recycling Center, Manhattan Project, 
 Nuclear Power, Nuclear Unit, Space Flight, 
 Nuclear Plant, SS Structure, Apollo Program, 
 Plastic, SS Component, Superconductor, Robotics, 
 Fusion Power, SDI Defence, Artillery, Mfg Plant, 
 SS Module

Mysticism    <- Ceremonial Burial

   -> Oracle, Astronomy, Philosophy, Copernicus, 
 Navigation, Medicine, Religion, Democracy, 
 University, Sail, Magellan, Physics, Shakespeare, 
 Cathedral, J.S. Bach, Michelangelo, Chemistry, 
 University (Imp), Theory of Gravity, Magnetism, 
 Steam Engine, Isaac Newton, Atomic Theory, 
 Explosives, Metallurgy, Frigate, Railroad, Ironclad, 
 Conscription, Cannon, Electricity, Darwin's Voyage, 
 Industrialization, Rifleman, Electronics, Transport, 
 Factory, Women's Suffrage, Steel, Corporation, 
 Communism, Hydro Plant, Hoover Dam, Computers, 
 Battleship, Refining, Genetic Eng., United Nations, 
 SETI Program, Power Plant, Combustion, 
 Cure for Cancer, Automobile, Cruiser, Flight, Armor, 
 Mass Production, Fighter, Advanced Flight, 
 Labor Union, Submarine, Mass Transit, Recycling, 
 Nuclear Fission, Bomber, Carrier, Rocketry, 
 Mech Infantry, Recycling Center, Manhattan Project, 
 Nuclear Power, Nuclear Unit, Space Flight, 
 Nuclear Plant, SS Structure, Apollo Program, 
 Plastic, SS Component, Superconductor, Robotics, 
 Fusion Power, SDI Defence, Artillery, Mfg Plant, 
 SS Module

Mathematics  <- Masonry, Alphabet

   -> Catapult, Astronomy, Copernicus, Navigation, 
 University, Sail, Magellan, Physics, Chemistry, 
 University (Imp), Theory of Gravity, Magnetism, 
 Steam Engine, Isaac Newton, Atomic Theory, 
 Explosives, Metallurgy, Frigate, Railroad, Ironclad, 
 Conscription, Cannon, Electricity, Darwin's Voyage, 
 Industrialization, Rifleman, Electronics, Transport, 
 Factory, Women's Suffrage, Steel, Corporation, 
 Communism, Hydro Plant, Hoover Dam, Computers, 
 Battleship, Refining, Genetic Eng., United Nations, 
 SETI Program, Power Plant, Combustion, 
 Cure for Cancer, Automobile, Cruiser, Flight, Armor, 
 Mass Production, Fighter, Advanced Flight, 
 Labor Union, Submarine, Mass Transit, Recycling, 
 Nuclear Fission, Bomber, Carrier, Rocketry, 
 Mech Infantry, Recycling Center, Manhattan Project, 
 Nuclear Power, Nuclear Unit, Space Flight, 
 Nuclear Plant, SS Structure, Apollo Program, 
 Plastic, SS Component, Superconductor, Robotics, 
 Fusion Power, SDI Defence, Artillery, Mfg Plant, 
 SS Module

Literacy<- Code of Laws, Writing, Alphabet

   -> Great Library, Republic, Philosophy, Banking, 
 Medicine, Religion, Democracy, University, 
 Invention, Bank, Shakespeare, Cathedral, J.S. Bach, 
 Michelangelo, Chemistry, University (Imp), 
 Theory of Gravity, Gunpowder, Steam Engine, 
 Isaac Newton, Atomic Theory, Explosives, Musketeer, 
 Metallurgy, Railroad, Ironclad, Conscription, 
 Cannon, Electricity, Darwin's Voyage, 
 Industrialization, Rifleman, Electronics, Transport, 
 Factory, Women's Suffrage, Steel, Corporation, 
 Communism, Hydro Plant, Hoover Dam, Computers, 
 Battleship, Refining, Genetic Eng., United Nations, 
 SETI Program, Power Plant, Combustion, 
 Cure for Cancer, Automobile, Cruiser, Flight, Armor, 
 Mass Production, Fighter, Advanced Flight, 
 Labor Union, Submarine, Mass Transit, Recycling, 
 Nuclear Fission, Bomber, Carrier, Rocketry, 
 Mech Infantry, Recycling Center, Manhattan Project, 
 Nuclear Power, Nuclear Unit, Space Flight, 
 Nuclear Plant, SS Structure, Apollo Program, 
 Plastic, SS Component, Superconductor, Robotics, 
 Fusion Power, SDI Defence, Artillery, Mfg Plant, 
 SS Module

Monarchy<- Code of Laws, Ceremonial Burial, Alphabet

   -> Feudalism, Chivalry, Knight

Trade   <- Currency, Code of Laws, Bronze Working, Alphabet

   -> Caravan, Banking, Medicine, Bank, Shakespeare, 
 Chemistry, Explosives, Conscription, 
 Industrialization, Rifleman, Transport, Factory, 
 Women's Suffrage, Steel, Corporation, Communism, 
 Battleship, Refining, Genetic Eng., United Nations, 
 Power Plant, Combustion, Cure for Cancer, 
 Automobile, Cruiser, Flight, Armor, Mass Production, 
 Fighter, Advanced Flight, Labor Union, Submarine, 
 Mass Transit, Recycling, Nuclear Fission, Bomber, 
 Carrier, Rocketry, Mech Infantry, Recycling Center, 
 Manhattan Project, Nuclear Power, Nuclear Unit, 
 Space Flight, Nuclear Plant, SS Structure, 
 Apollo Program, Plastic, SS Component, 
 Superconductor, Robotics, Fusion Power, SDI Defence, 
 Artillery, Mfg Plant, SS Module

Construction <- Currency, Masonry, Bronze Working

   -> Aqueduct, Colosseum, Fortress, Engineering, 
 Bridge Building, Invention, Gunpowder, Steam Engine, 
 Explosives, Musketeer, Metallurgy, Railroad, 
 Ironclad, Conscription, Cannon, Electricity, 
 Darwin's Voyage, Industrialization, Rifleman, 
 Electronics, Transport, Factory, Women's Suffrage, 
 Steel, Corporation, Communism, Hydro Plant, 
 Hoover Dam, Computers, Battleship, Refining, 
 Genetic Eng., United Nations, SETI Program, 
 Power Plant, Combustion, Cure for Cancer, 
 Automobile, Cruiser, Flight, Armor, Mass Production, 
 Fighter, Advanced Flight, Labor Union, Submarine, 
 Mass Transit, Recycling, Nuclear Fission, Bomber, 
 Carrier, Rocketry, Mech Infantry, Recycling Center, 
 Manhattan Project, Nuclear Power, Nuclear Unit, 
 Space Flight, Nuclear Plant, SS Structure, 
 Apollo Program, Plastic, SS Component, 
 Superconductor, Robotics, Fusion Power, SDI Defence, 
 Artillery, Mfg Plant, SS Module

Astronomy    <- Mathematics, Mysticism, Masonry, Ceremonial Burial, 
 Alphabet

   -> Copernicus, Navigation, Sail, Magellan, Physics, 
 Theory of Gravity, Magnetism, Steam Engine, 
 Isaac Newton, Atomic Theory, Frigate, Railroad, 
 Ironclad, Electricity, Darwin's Voyage, 
 Industrialization, Electronics, Transport, Factory, 
 Women's Suffrage, Steel, Corporation, Communism, 
 Hydro Plant, Hoover Dam, Computers, Battleship, 
 Refining, Genetic Eng., United Nations, 
 SETI Program, Power Plant, Combustion, 
 Cure for Cancer, Automobile, Cruiser, Flight, Armor, 
 Mass Production, Fighter, Advanced Flight, 
 Labor Union, Submarine, Mass Transit, Recycling, 
 Nuclear Fission, Bomber, Carrier, Rocketry, 
 Mech Infantry, Recycling Center, Manhattan Project, 
 Nuclear Power, Nuclear Unit, Space Flight, 
 Nuclear Plant, SS Structure, Apollo Program, 
 Plastic, SS Component, Superconductor, Robotics, 
 Fusion Power, SDI Defence, Artillery, Mfg Plant, 
 SS Module

Republic<- Literacy, Code of Laws, Writing, Alphabet

   -> Banking, Bank, Conscription, Industrialization, 
 Rifleman, Transport, Factory, Women's Suffrage, 
 Steel, Corporation, Communism, Battleship, Refining, 
 Genetic Eng., United Nations, Power Plant, 
 Combustion, Cure for Cancer, Automobile, Cruiser, 
 Flight, Armor, Mass Production, Fighter, 
 Advanced Flight, Labor Union, Submarine, 
 Mass Transit, Recycling, Nuclear Fission, Bomber, 
 Carrier, Rocketry, Mech Infantry, Recycling Center, 
 Manhattan Project, Nuclear Power, Nuclear Unit, 
 Space Flight, Nuclear Plant, SS Structure, 
 Apollo Program, Plastic, SS Component, 
 Superconductor, Robotics, Fusion Power, SDI Defence, 
 Artillery, Mfg Plant, SS Module

Philosophy   <- Literacy, Mysticism, Code of Laws, Writing, 
 Ceremonial Burial, Alphabet

   -> Medicine, Religion, Democracy, University, 
 Shakespeare, Cathedral, J.S. Bach, Michelangelo, 
 Chemistry, University (Imp), Theory of Gravity, 
 Isaac Newton, Atomic Theory, Explosives, Metallurgy, 
 Conscription, Cannon, Electricity, Rifleman, 
 Electronics, Steel, Communism, Hydro Plant, 
 Hoover Dam, Computers, Battleship, Refining, 
 Genetic Eng., United Nations, SETI Program, 
 Power Plant, Combustion, Cure for Cancer, 
 Automobile, Cruiser, Flight, Armor, Mass Production, 
 Fighter, Advanced Flight, Labor Union, Submarine, 
 Mass Transit, Recycling, Nuclear Fission, Bomber, 
 Carrier, Rocketry, Mech Infantry, Recycling Center, 
 Manhattan Project, Nuclear Power, Nuclear Unit, 
 Space Flight, Nuclear Plant, SS Structure, 
 Apollo Program, Plastic, SS Component, 
 Superconductor, Robotics, Fusion Power, SDI Defence, 
 Artillery, Mfg Plant, SS Module

Feudalism    <- Monarchy, Code of Laws, Masonry, Ceremonial Burial, 
 Alphabet

   -> Chivalry, Knight

Engineering  <- Construction, Currency, The Wheel, Masonry, 
 Bronze Working

   -> Invention, Gunpowder, Steam Engine, Explosives, 
 Musketeer, Metallurgy, Railroad, Ironclad, 
 Conscription, Cannon, Electricity, Darwin's Voyage, 
 Industrialization, Rifleman, Electronics, Transport, 
 Factory, Women's Suffrage, Steel, Corporation, 
 Communism, Hydro Plant, Hoover Dam, Computers, 
 Battleship, Refining, Genetic Eng., United Nations, 
 SETI Program, Power Plant, Combustion, 
 Cure for Cancer, Automobile, Cruiser, Flight, Armor, 
 Mass Production, Fighter, Advanced Flight, 
 Labor Union, Submarine, Mass Transit, Recycling, 
 Nuclear Fission, Bomber, Carrier, Rocketry, 
 Mech Infantry, Recycling Center, Manhattan Project, 
 Nuclear Power, Nuclear Unit, Space Flight, 
 Nuclear Plant, SS Structure, Apollo Program, 
 Plastic, SS Component, Superconductor, Robotics, 
 Fusion Power, SDI Defence, Artillery, Mfg Plant, 
 SS Module

Bridge Building   <- Construction, Currency, Iron Working, Masonry, 
 Bronze Working

   -> Railroad, Darwin's Voyage, Industrialization, 
 Transport, Factory, Women's Suffrage, Steel, 
 Corporation, Communism, Battleship, Refining, 
 Genetic Eng., United Nations, Power Plant, 
 Combustion, Cure for Cancer, Automobile, Cruiser, 
 Flight, Armor, Mass Production, Fighter, 
 Advanced Flight, Labor Union, Submarine, 
 Mass Transit, Recycling, Nuclear Fission, Bomber, 
 Carrier, Rocketry, Mech Infantry, Recycling Center, 
 Manhattan Project, Nuclear Power, Nuclear Unit, 
 Space Flight, Nuclear Plant, SS Structure, 
 Apollo Program, Plastic, SS Component, 
 Superconductor, Robotics, Fusion Power, SDI Defence, 
 Artillery, Mfg Plant, SS Module

Navigation   <- Astronomy, Mathematics, Mysticism, Map Making, 
 Masonry, Ceremonial Burial, Alphabet

   -> Sail, Magellan, Physics, Magnetism, Steam Engine, 
 Atomic Theory, Frigate, Railroad, Ironclad, 
 Electricity, Darwin's Voyage, Industrialization, 
 Electronics, Transport, Factory, Women's Suffrage, 
 Steel, Corporation, Communism, Hydro Plant, 
 Hoover Dam, Computers, Battleship, Refining, 
 Genetic Eng., United Nations, SETI Program, 
 Power Plant, Combustion, Cure for Cancer, 
 Automobile, Cruiser, Flight, Armor, Mass Production, 
 Fighter, Advanced Flight, Labor Union, Submarine, 
 Mass Transit, Recycling, Nuclear Fission, Bomber, 
 Carrier, Rocketry, Mech Infantry, Recycling Center, 
 Manhattan Project, Nuclear Power, Nuclear Unit, 
 Space Flight, Nuclear Plant, SS Structure, 
 Apollo Program, Plastic, SS Component, 
 Superconductor, Robotics, Fusion Power, SDI Defence, 
 Artillery, Mfg Plant, SS Module

Banking <- Republic, Trade, Literacy, Currency, Code of Laws, 
 Writing, Bronze Working, Alphabet

   -> Bank, Industrialization, Transport, Factory, 
 Women's Suffrage, Steel, Corporation, Communism, 
 Battleship, Refining, Genetic Eng., United Nations, 
 Power Plant, Combustion, Cure for Cancer, 
 Automobile, Cruiser, Flight, Armor, Mass Production, 
 Fighter, Advanced Flight, Labor Union, Submarine, 
 Mass Transit, Recycling, Nuclear Fission, Bomber, 
 Carrier, Rocketry, Mech Infantry, Recycling Center, 
 Manhattan Project, Nuclear Power, Nuclear Unit, 
 Space Flight, Nuclear Plant, SS Structure, 
 Apollo Program, Plastic, SS Component, 
 Superconductor, Robotics, Fusion Power, SDI Defence, 
 Artillery, Mfg Plant, SS Module

Medicine<- Philosophy, Trade, Literacy, Mysticism, Currency, 
 Code of Laws, Writing, Ceremonial Burial, 
 Bronze Working, Alphabet

   -> Shakespeare, Chemistry, Explosives, Conscription, 
 Rifleman, Refining, Genetic Eng., Power Plant, 
 Combustion, Cure for Cancer, Automobile, Cruiser, 
 Flight, Armor, Mass Production, Fighter, 
 Advanced Flight, Labor Union, Submarine, 
 Mass Transit, Recycling, Nuclear Fission, Bomber, 
 Carrier, Rocketry, Mech Infantry, Recycling Center, 
 Manhattan Project, Nuclear Power, Nuclear Unit, 
 Space Flight, Nuclear Plant, SS Structure, 
 Apollo Program, Plastic, SS Component, 
 Superconductor, Robotics, Fusion Power, SDI Defence, 
 Artillery, Mfg Plant, SS Module

Religion<- Philosophy, Literacy, Mysticism, Code of Laws, 
 Writing, Ceremonial Burial, Alphabet

   -> Cathedral, J.S. Bach, Michelangelo

Democracy    <- Philosophy, Literacy, Mysticism, Code of Laws, 
 Writing, Ceremonial Burial, Alphabet

   -> Recycling, Recycling Center

University   <- Philosophy, Literacy, Mathematics, Mysticism, 
 Code of Laws, Writing, Masonry, Ceremonial Burial, 
 Alphabet

   -> Chemistry, University (Imp), Theory of Gravity, 
 Isaac Newton, Atomic Theory, Explosives, Metallurgy, 
 Conscription, Cannon, Electricity, Rifleman, 
 Electronics, Steel, Hydro Plant, Hoover Dam, 
 Computers, Battleship, Refining, SETI Program, 
 Power Plant, Combustion, Automobile, Cruiser, 
 Flight, Armor, Mass Production, Fighter, 
 Advanced Flight, Labor Union, Submarine, 
 Mass Transit, Recycling, Nuclear Fission, Bomber, 
 Carrier, Rocketry, Mech Infantry, Recycling Center, 
 Manhattan Project, Nuclear Power, Nuclear Unit, 
 Space Flight, Nuclear Plant, SS Structure, 
 Apollo Program, Plastic, SS Component, 
 Superconductor, Robotics, Fusion Power, SDI Defence, 
 Artillery, Mfg Plant, SS Module

Chivalry<- Feudalism, Monarchy, Code of Laws, Horseback Riding, 
 Masonry, Ceremonial Burial, Alphabet

   -> Knight

Invention    <- Engineering, Construction, Literacy, Currency, 
 Code of Laws, Writing, The Wheel, Masonry, 
 Bronze Working, Alphabet

   -> Gunpowder, Steam Engine, Explosives, Musketeer, 
 Metallurgy, Railroad, Ironclad, Conscription, 
 Cannon, Electricity, Darwin's Voyage, 
 Industrialization, Rifleman, Electronics, Transport, 
 Factory, Women's Suffrage, Steel, Corporation, 
 Communism, Hydro Plant, Hoover Dam, Computers, 
 Battleship, Refining, Genetic Eng., United Nations, 
 SETI Program, Power Plant, Combustion, 
 Cure for Cancer, Automobile, Cruiser, Flight, Armor, 
 Mass Production, Fighter, Advanced Flight, 
 Labor Union, Submarine, Mass Transit, Recycling, 
 Nuclear Fission, Bomber, Carrier, Rocketry, 
 Mech Infantry, Recycling Center, Manhattan Project, 
 Nuclear Power, Nuclear Unit, Space Flight, 
 Nuclear Plant, SS Structure, Apollo Program, 
 Plastic, SS Component, Superconductor, Robotics, 
 Fusion Power, SDI Defence, Artillery, Mfg Plant, 
 SS Module

Physics <- Navigation, Astronomy, Mathematics, Mysticism, 
 Map Making, Masonry, Ceremonial Burial, Alphabet

   -> Magnetism, Steam Engine, Atomic Theory, Frigate, 
 Railroad, Ironclad, Electricity, Darwin's Voyage, 
 Industrialization, Electronics, Transport, Factory, 
 Women's Suffrage, Steel, Corporation, Communism, 
 Hydro Plant, Hoover Dam, Computers, Battleship, 
 Refining, Genetic Eng., United Nations, 
 SETI Program, Power Plant, Combustion, 
 Cure for Cancer, Automobile, Cruiser, Flight, Armor, 
 Mass Production, Fighter, Advanced Flight, 
 Labor Union, Submarine, Mass Transit, Recycling, 
 Nuclear Fission, Bomber, Carrier, Rocketry, 
 Mech Infantry, Recycling Center, Manhattan Project, 
 Nuclear Power, Nuclear Unit, Space Flight, 
 Nuclear Plant, SS Structure, Apollo Program, 
 Plastic, SS Component, Superconductor, Robotics, 
 Fusion Power, SDI Defence, Artillery, Mfg Plant, 
 SS Module

Chemistry    <- University, Medicine, Philosophy, Trade, Literacy, 
 Mathematics, Mysticism, Currency, Code of Laws, 
 Writing, Masonry, Ceremonial Burial, Bronze Working, 
 Alphabet

   -> Explosives, Conscription, Rifleman, Refining, 
 Power Plant, Combustion, Automobile, Cruiser, 
 Flight, Armor, Mass Production, Fighter, 
 Advanced Flight, Labor Union, Submarine, 
 Mass Transit, Recycling, Nuclear Fission, Bomber, 
 Carrier, Rocketry, Mech Infantry, Recycling Center, 
 Manhattan Project, Nuclear Power, Nuclear Unit, 
 Space Flight, Nuclear Plant, SS Structure, 
 Apollo Program, Plastic, SS Component, 
 Superconductor, Robotics, Fusion Power, SDI Defence, 
 Artillery, Mfg Plant, SS Module

Theory of Gravity <- University, Philosophy, Astronomy, Literacy, 
 Mathematics, Mysticism, Code of Laws, Writing, 
 Masonry, Ceremonial Burial, Alphabet

   -> Isaac Newton, Atomic Theory, Nuclear Fission, 
 Manhattan Project, Nuclear Power, Nuclear Plant, 
 Fusion Power

Gunpowder    <- Invention, Engineering, Construction, Literacy, 
 Currency, Iron Working, Code of Laws, Writing, 
 The Wheel, Masonry, Bronze Working, Alphabet

   -> Explosives, Musketeer, Metallurgy, Conscription, 
 Cannon, Electricity, Rifleman, Electronics, Steel, 
 Hydro Plant, Hoover Dam, Computers, Battleship, 
 SETI Program, Combustion, Automobile, Cruiser, 
 Flight, Armor, Mass Production, Fighter, 
 Advanced Flight, Labor Union, Submarine, 
 Mass Transit, Recycling, Nuclear Fission, Bomber, 
 Carrier, Rocketry, Mech Infantry, Recycling Center, 
 Manhattan Project, Nuclear Power, Nuclear Unit, 
 Space Flight, Nuclear Plant, SS Structure, 
 Apollo Program, Plastic, SS Component, 
 Superconductor, Robotics, Fusion Power, SDI Defence, 
 Artillery, Mfg Plant, SS Module

Magnetism    <- Physics, Navigation, Astronomy, Mathematics, 
 Mysticism, Map Making, Masonry, Ceremonial Burial, 
 Alphabet

   -> Frigate, Electricity, Electronics, Hydro Plant, 
 Hoover Dam, Computers, SETI Program, 
 Advanced Flight, Bomber, Carrier, Rocketry, 
 Nuclear Power, Nuclear Unit, Space Flight, 
 Nuclear Plant, SS Structure, Apollo Program, 
 Plastic, SS Component, Superconductor, Robotics, 
 Fusion Power, SDI Defence, Artillery, Mfg Plant, 
 SS Module

Steam Engine <- Physics, Invention, Navigation, Engineering, 
 Astronomy, Construction, Literacy, Mathematics, 
 Mysticism, Currency, Code of Laws, Writing, 
 Map Making, The Wheel, Masonry, Ceremonial Burial, 
 Bronze Working, Alphabet

   -> Railroad, Ironclad, Darwin's Voyage, 
 Industrialization, Transport, Factory, 
 Women's Suffrage, Steel, Corporation, Communism, 
 Battleship, Refining, Genetic Eng., United Nations, 
 Power Plant, Combustion, Cure for Cancer, 
 Automobile, Cruiser, Flight, Armor, Mass Production, 
 Fighter, Advanced Flight, Labor Union, Submarine, 
 Mass Transit, Recycling, Nuclear Fission, Bomber, 
 Carrier, Rocketry, Mech Infantry, Recycling Center, 
 Manhattan Project, Nuclear Power, Nuclear Unit, 
 Space Flight, Nuclear Plant, SS Structure, 
 Apollo Program, Plastic, SS Component, 
 Superconductor, Robotics, Fusion Power, SDI Defence, 
 Artillery, Mfg Plant, SS Module

Atomic Theory<- Theory of Gravity, Physics, University, Navigation, 
 Philosophy, Astronomy, Literacy, Mathematics, 
 Mysticism, Code of Laws, Writing, Map Making, 
 Masonry, Ceremonial Burial, Alphabet

   -> Nuclear Fission, Manhattan Project, Nuclear Power, 
 Nuclear Plant, Fusion Power

Explosives   <- Gunpowder, Chemistry, Invention, University, 
 Medicine, Engineering, Philosophy, Construction, 
 Trade, Literacy, Mathematics, Mysticism, Currency, 
 Iron Working, Code of Laws, Writing, The Wheel, 
 Masonry, Ceremonial Burial, Bronze Working, 
 Alphabet

   -> Conscription, Rifleman, Combustion, Automobile, 
 Cruiser, Flight, Armor, Mass Production, Fighter, 
 Advanced Flight, Labor Union, Submarine, 
 Mass Transit, Recycling, Nuclear Fission, Bomber, 
 Carrier, Rocketry, Mech Infantry, Recycling Center, 
 Manhattan Project, Nuclear Power, Nuclear Unit, 
 Space Flight, Nuclear Plant, SS Structure, 
 Apollo Program, Plastic, SS Component, 
 Superconductor, Robotics, Fusion Power, SDI Defence, 
 Artillery, Mfg Plant, SS Module

Metallurgy   <- Gunpowder, Invention, University, Engineering, 
 Philosophy, Construction, Literacy, Mathematics, 
 Mysticism, Currency, Iron Working, Code of Laws, 
 Writing, The Wheel, Masonry, Ceremonial Burial, 
 Bronze Working, Alphabet

   -> Cannon, Electricity, Electronics, Steel, 
 Hydro Plant, Hoover Dam, Computers, Battleship, 
 SETI Program, Automobile, Armor, Mass Production, 
 Advanced Flight, Labor Union, Submarine, 
 Mass Transit, Recycling, Nuclear Fission, Bomber, 
 Carrier, Rocketry, Mech Infantry, Recycling Center, 
 Manhattan Project, Nuclear Power, Nuclear Unit, 
 Space Flight, Nuclear Plant, SS Structure, 
 Apollo Program, Plastic, SS Component, 
 Superconductor, Robotics, Fusion Power, SDI Defence, 
 Artillery, Mfg Plant, SS Module

Railroad<- Steam Engine, Physics, Invention, Navigation, 
 Bridge Building, Engineering, Astronomy, 
 Construction, Literacy, Mathematics, Mysticism, 
 Currency, Iron Working, Code of Laws, Writing, 
 Map Making, The Wheel, Masonry, Ceremonial Burial, 
 Bronze Working, Alphabet

   -> Darwin's Voyage, Industrialization, Transport, 
 Factory, Women's Suffrage, Steel, Corporation, 
 Communism, Battleship, Refining, Genetic Eng., 
 United Nations, Power Plant, Combustion, 
 Cure for Cancer, Automobile, Cruiser, Flight, Armor, 
 Mass Production, Fighter, Advanced Flight, 
 Labor Union, Submarine, Mass Transit, Recycling, 
 Nuclear Fission, Bomber, Carrier, Rocketry, 
 Mech Infantry, Recycling Center, Manhattan Project, 
 Nuclear Power, Nuclear Unit, Space Flight, 
 Nuclear Plant, SS Structure, Apollo Program, 
 Plastic, SS Component, Superconductor, Robotics, 
 Fusion Power, SDI Defence, Artillery, Mfg Plant, 
 SS Module

Conscription <- Explosives, Gunpowder, Chemistry, Invention, 
 University, Medicine, Engineering, Philosophy, 
 Republic, Construction, Trade, Literacy, 
 Mathematics, Mysticism, Currency, Iron Working, 
 Code of Laws, Writing, The Wheel, Masonry, 
 Ceremonial Burial, Bronze Working, Alphabet

   -> Rifleman

Electricity  <- Metallurgy, Magnetism, Gunpowder, Physics, 
 Invention, University, Navigation, Engineering, 
 Philosophy, Astronomy, Construction, Literacy, 
 Mathematics, Mysticism, Currency, Iron Working, 
 Code of Laws, Writing, Map Making, The Wheel, 
 Masonry, Ceremonial Burial, Bronze Working, 
 Alphabet

   -> Electronics, Hydro Plant, Hoover Dam, Computers, 
 SETI Program, Advanced Flight, Bomber, Carrier, 
 Rocketry, Nuclear Power, Nuclear Unit, Space Flight, 
 Nuclear Plant, SS Structure, Apollo Program, 
 Plastic, SS Component, Superconductor, Robotics, 
 Fusion Power, SDI Defence, Artillery, Mfg Plant, 
 SS Module

Industrialization <- Railroad, Steam Engine, Physics, Invention, Banking, 
 Navigation, Bridge Building, Engineering, Republic, 
 Astronomy, Construction, Trade, Literacy, 
 Mathematics, Mysticism, Currency, Iron Working, 
 Code of Laws, Writing, Map Making, The Wheel, 
 Masonry, Ceremonial Burial, Bronze Working, 
 Alphabet

   -> Transport, Factory, Women's Suffrage, Steel, 
 Corporation, Communism, Battleship, Refining, 
 Genetic Eng., United Nations, Power Plant, 
 Combustion, Cure for Cancer, Automobile, Cruiser, 
 Flight, Armor, Mass Production, Fighter, 
 Advanced Flight, Labor Union, Submarine, 
 Mass Transit, Recycling, Nuclear Fission, Bomber, 
 Carrier, Rocketry, Mech Infantry, Recycling Center, 
 Manhattan Project, Nuclear Power, Nuclear Unit, 
 Space Flight, Nuclear Plant, SS Structure, 
 Apollo Program, Plastic, SS Component, 
 Superconductor, Robotics, Fusion Power, SDI Defence, 
 Artillery, Mfg Plant, SS Module

Electronics  <- Electricity, Metallurgy, Magnetism, Gunpowder, 
 Physics, Invention, University, Navigation, 
 Engineering, Philosophy, Astronomy, Construction, 
 Literacy, Mathematics, Mysticism, Currency, 
 Iron Working, Code of Laws, Writing, Map Making, 
 The Wheel, Masonry, Ceremonial Burial, 
 Bronze Working, Alphabet

   -> Hydro Plant, Hoover Dam, Computers, SETI Program, 
 Rocketry, Nuclear Power, Nuclear Unit, Space Flight, 
 Nuclear Plant, SS Structure, Apollo Program, 
 Plastic, SS Component, Superconductor, Robotics, 
 Fusion Power, SDI Defence, Artillery, Mfg Plant, 
 SS Module

Steel   <- Industrialization, Railroad, Metallurgy, 
 Steam Engine, Gunpowder, Physics, Invention, 
 University, Banking, Navigation, Bridge Building, 
 Engineering, Philosophy, Republic, Astronomy, 
 Construction, Trade, Literacy, Mathematics, 
 Mysticism, Currency, Iron Working, Code of Laws, 
 Writing, Map Making, The Wheel, Masonry, 
 Ceremonial Burial, Bronze Working, Alphabet

   -> Battleship, Automobile, Armor, Mass Production, 
 Labor Union, Submarine, Mass Transit, Recycling, 
 Nuclear Fission, Mech Infantry, Recycling Center, 
 Manhattan Project, Nuclear Power, Nuclear Plant, 
 Superconductor, Fusion Power, SDI Defence

Corporation  <- Industrialization, Railroad, Steam Engine, Physics, 
 Invention, Banking, Navigation, Bridge Building, 
 Engineering, Republic, Astronomy, Construction, 
 Trade, Literacy, Mathematics, Mysticism, Currency, 
 Iron Working, Code of Laws, Writing, Map Making, 
 The Wheel, Masonry, Ceremonial Burial, 
 Bronze Working, Alphabet

   -> Refining, Genetic Eng., Power Plant, Combustion, 
 Cure for Cancer, Automobile, Cruiser, Flight, Armor, 
 Mass Production, Fighter, Advanced Flight, 
 Labor Union, Submarine, Mass Transit, Recycling, 
 Nuclear Fission, Bomber, Carrier, Rocketry, 
 Mech Infantry, Recycling Center, Manhattan Project, 
 Nuclear Power, Nuclear Unit, Space Flight, 
 Nuclear Plant, SS Structure, Apollo Program, 
 Plastic, SS Component, Superconductor, Robotics, 
 Fusion Power, SDI Defence, Artillery, Mfg Plant, 
 SS Module

Communism    <- Industrialization, Railroad, Steam Engine, Physics, 
 Invention, Banking, Navigation, Bridge Building, 
 Engineering, Philosophy, Republic, Astronomy, 
 Construction, Trade, Literacy, Mathematics, 
 Mysticism, Currency, Iron Working, Code of Laws, 
 Writing, Map Making, The Wheel, Masonry, 
 Ceremonial Burial, Bronze Working, Alphabet

   -> United Nations, Labor Union, Mech Infantry

Computers    <- Electronics, Electricity, Metallurgy, Magnetism, 
 Gunpowder, Physics, Invention, University, 
 Navigation, Engineering, Philosophy, Astronomy, 
 Construction, Literacy, Mathematics, Mysticism, 
 Currency, Iron Working, Code of Laws, Writing, 
 Map Making, The Wheel, Masonry, Ceremonial Burial, 
 Bronze Working, Alphabet

   -> SETI Program, Space Flight, SS Structure, 
 Apollo Program, Plastic, SS Component, 
 Superconductor, Robotics, Fusion Power, SDI Defence, 
 Artillery, Mfg Plant, SS Module

Refining<- Corporation, Industrialization, Railroad, 
 Steam Engine, Chemistry, Physics, Invention, 
 University, Medicine, Banking, Navigation, 
 Bridge Building, Engineering, Philosophy, Republic, 
 Astronomy, Construction, Trade, Literacy, 
 Mathematics, Mysticism, Currency, Iron Working, 
 Code of Laws, Writing, Map Making, The Wheel, 
 Masonry, Ceremonial Burial, Bronze Working, 
 Alphabet

   -> Power Plant, Combustion, Automobile, Cruiser, 
 Flight, Armor, Mass Production, Fighter, 
 Advanced Flight, Labor Union, Submarine, 
 Mass Transit, Recycling, Nuclear Fission, Bomber, 
 Carrier, Rocketry, Mech Infantry, Recycling Center, 
 Manhattan Project, Nuclear Power, Nuclear Unit, 
 Space Flight, Nuclear Plant, SS Structure, 
 Apollo Program, Plastic, SS Component, 
 Superconductor, Robotics, Fusion Power, SDI Defence, 
 Artillery, Mfg Plant, SS Module

Genetic Eng. <- Corporation, Industrialization, Railroad, 
 Steam Engine, Physics, Invention, Medicine, Banking, 
 Navigation, Bridge Building, Engineering, 
 Philosophy, Republic, Astronomy, Construction, 
 Trade, Literacy, Mathematics, Mysticism, Currency, 
 Iron Working, Code of Laws, Writing, Map Making, 
 The Wheel, Masonry, Ceremonial Burial, 
 Bronze Working, Alphabet

   -> Cure for Cancer

Combustion   <- Refining, Corporation, Industrialization, Railroad, 
 Explosives, Steam Engine, Gunpowder, Chemistry, 
 Physics, Invention, University, Medicine, Banking, 
 Navigation, Bridge Building, Engineering, 
 Philosophy, Republic, Astronomy, Construction, 
 Trade, Literacy, Mathematics, Mysticism, Currency, 
 Iron Working, Code of Laws, Writing, Map Making, 
 The Wheel, Masonry, Ceremonial Burial, 
 Bronze Working, Alphabet

   -> Automobile, Cruiser, Flight, Armor, Mass Production, 
 Fighter, Advanced Flight, Labor Union, Submarine, 
 Mass Transit, Recycling, Nuclear Fission, Bomber, 
 Carrier, Rocketry, Mech Infantry, Recycling Center, 
 Manhattan Project, Nuclear Power, Nuclear Unit, 
 Space Flight, Nuclear Plant, SS Structure, 
 Apollo Program, Plastic, SS Component, 
 Superconductor, Robotics, Fusion Power, SDI Defence, 
 Artillery, Mfg Plant, SS Module

Automobile   <- Combustion, Refining, Corporation, Steel, 
 Industrialization, Railroad, Metallurgy, Explosives, 
 Steam Engine, Gunpowder, Chemistry, Physics, 
 Invention, University, Medicine, Banking, 
 Navigation, Bridge Building, Engineering, 
 Philosophy, Republic, Astronomy, Construction, 
 Trade, Literacy, Mathematics, Mysticism, Currency, 
 Iron Working, Code of Laws, Writing, Map Making, 
 The Wheel, Masonry, Ceremonial Burial, 
 Bronze Working, Alphabet

   -> Armor, Mass Production, Labor Union, Submarine, 
 Mass Transit, Recycling, Nuclear Fission, 
 Mech Infantry, Recycling Center, Manhattan Project, 
 Nuclear Power, Nuclear Plant, Superconductor, 
 Fusion Power, SDI Defence

Flight  <- Combustion, Refining, Corporation, 
 Industrialization, Railroad, Explosives, 
 Steam Engine, Gunpowder, Chemistry, Physics, 
 Invention, University, Medicine, Banking, 
 Navigation, Bridge Building, Engineering, 
 Philosophy, Republic, Astronomy, Construction, 
 Trade, Literacy, Mathematics, Mysticism, Currency, 
 Iron Working, Code of Laws, Writing, Map Making, 
 The Wheel, Masonry, Ceremonial Burial, 
 Bronze Working, Alphabet

   -> Fighter, Advanced Flight, Bomber, Carrier, Rocketry, 
 Nuclear Unit, Space Flight, SS Structure, 
 Apollo Program, Plastic, SS Component, 
 Superconductor, Robotics, Fusion Power, SDI Defence, 
 Artillery, Mfg Plant, SS Module

Mass Production   <- Automobile, Combustion, Refining, Corporation, 
 Steel, Industrialization, Railroad, Metallurgy, 
 Explosives, Steam Engine, Gunpowder, Chemistry, 
 Physics, Invention, University, Medicine, Banking, 
 Navigation, Bridge Building, Engineering, 
 Philosophy, Republic, Astronomy, Construction, 
 Trade, Literacy, Mathematics, Mysticism, Currency, 
 Iron Working, Code of Laws, Writing, Map Making, 
 The Wheel, Masonry, Ceremonial Burial, 
 Bronze Working, Alphabet

   -> Labor Union, Submarine, Mass Transit, Recycling, 
 Nuclear Fission, Mech Infantry, Recycling Center, 
 Manhattan Project, Nuclear Power, Nuclear Plant, 
 Superconductor, Fusion Power, SDI Defence

Advanced Flight   <- Flight, Combustion, Refining, Corporation, 
 Industrialization, Electricity, Railroad, 
 Metallurgy, Explosives, Steam Engine, Magnetism, 
 Gunpowder, Chemistry, Physics, Invention, 
 University, Medicine, Banking, Navigation, 
 Bridge Building, Engineering, Philosophy, Republic, 
 Astronomy, Construction, Trade, Literacy, 
 Mathematics, Mysticism, Currency, Iron Working, 
 Code of Laws, Writing, Map Making, The Wheel, 
 Masonry, Ceremonial Burial, Bronze Working, 
 Alphabet

   -> Bomber, Carrier, Rocketry, Nuclear Unit, 
 Space Flight, SS Structure, Apollo Program, Plastic, 
 SS Component, Superconductor, Robotics, 
 Fusion Power, SDI Defence, Artillery, Mfg Plant, 
 SS Module

Labor Union  <- Mass Production, Automobile, Combustion, Refining, 
 Communism, Corporation, Steel, Industrialization, 
 Railroad, Metallurgy, Explosives, Steam Engine, 
 Gunpowder, Chemistry, Physics, Invention, 
 University, Medicine, Banking, Navigation, 
 Bridge Building, Engineering, Philosophy, Republic, 
 Astronomy, Construction, Trade, Literacy, 
 Mathematics, Mysticism, Currency, Iron Working, 
 Code of Laws, Writing, Map Making, The Wheel, 
 Masonry, Ceremonial Burial, Bronze Working, 
 Alphabet

   -> Mech Infantry

Recycling    <- Mass Production, Automobile, Combustion, Refining, 
 Corporation, Steel, Industrialization, Railroad, 
 Metallurgy, Explosives, Steam Engine, Gunpowder, 
 Chemistry, Physics, Invention, University, 
 Democracy, Medicine, Banking, Navigation, 
 Bridge Building, Engineering, Philosophy, Republic, 
 Astronomy, Construction, Trade, Literacy, 
 Mathematics, Mysticism, Currency, Iron Working, 
 Code of Laws, Writing, Map Making, The Wheel, 
 Masonry, Ceremonial Burial, Bronze Working, 
 Alphabet

   -> Recycling Center

Nuclear Fission   <- Mass Production, Automobile, Combustion, Refining, 
 Corporation, Steel, Industrialization, Railroad, 
 Metallurgy, Explosives, Atomic Theory, Steam Engine, 
 Gunpowder, Theory of Gravity, Chemistry, Physics, 
 Invention, University, Medicine, Banking, 
 Navigation, Bridge Building, Engineering, 
 Philosophy, Republic, Astronomy, Construction, 
 Trade, Literacy, Mathematics, Mysticism, Currency, 
 Iron Working, Code of Laws, Writing, Map Making, 
 The Wheel, Masonry, Ceremonial Burial, 
 Bronze Working, Alphabet

   -> Manhattan Project, Nuclear Power, Nuclear Plant, 
 Fusion Power

Rocketry<- Advanced Flight, Flight, Combustion, Refining, 
 Corporation, Electronics, Industrialization, 
 Electricity, Railroad, Metallurgy, Explosives, 
 Steam Engine, Magnetism, Gunpowder, Chemistry, 
 Physics, Invention, University, Medicine, Banking, 
 Navigation, Bridge Building, Engineering, 
 Philosophy, Republic, Astronomy, Construction, 
 Trade, Literacy, Mathematics, Mysticism, Currency, 
 Iron Working, Code of Laws, Writing, Map Making, 
 The Wheel, Masonry, Ceremonial Burial, 
 Bronze Working, Alphabet

   -> Nuclear Unit, Space Flight, SS Structure, 
 Apollo Program, Plastic, SS Component, 
 Superconductor, Robotics, Fusion Power, SDI Defence, 
 Artillery, Mfg Plant, SS Module

Nuclear Power<- Nuclear Fission, Mass Production, Automobile, 
 Combustion, Refining, Corporation, Steel, 
 Electronics, Industrialization, Electricity, 
 Railroad, Metallurgy, Explosives, Atomic Theory, 
 Steam Engine, Magnetism, Gunpowder, 
 Theory of Gravity, Chemistry, Physics, Invention, 
 University, Medicine, Banking, Navigation, 
 Bridge Building, Engineering, Philosophy, Republic, 
 Astronomy, Construction, Trade, Literacy, 
 Mathematics, Mysticism, Currency, Iron Working, 
 Code of Laws, Writing, Map Making, The Wheel, 
 Masonry, Ceremonial Burial, Bronze Working, 
 Alphabet

   -> Nuclear Plant, Fusion Power

Space Flight <- Rocketry, Advanced Flight, Flight, Combustion, 
 Refining, Computers, Corporation, Electronics, 
 Industrialization, Electricity, Railroad, 
 Metallurgy, Explosives, Steam Engine, Magnetism, 
 Gunpowder, Chemistry, Physics, Invention, 
 University, Medicine, Banking, Navigation, 
 Bridge Building, Engineering, Philosophy, Republic, 
 Astronomy, Construction, Trade, Literacy, 
 Mathematics, Mysticism, Currency, Iron Working, 
 Code of Laws, Writing, Map Making, The Wheel, 
 Masonry, Ceremonial Burial, Bronze Working, 
 Alphabet

   -> SS Structure, Apollo Program, Plastic, SS Component, 
 Superconductor, Robotics, Fusion Power, SDI Defence, 
 Artillery, Mfg Plant, SS Module

Plastic <- Space Flight, Rocketry, Advanced Flight, Flight, 
 Combustion, Refining, Computers, Corporation, 
 Electronics, Industrialization, Electricity, 
 Railroad, Metallurgy, Explosives, Steam Engine, 
 Magnetism, Gunpowder, Chemistry, Physics, Invention, 
 University, Medicine, Banking, Navigation, 
 Bridge Building, Engineering, Philosophy, Republic, 
 Astronomy, Construction, Trade, Literacy, 
 Mathematics, Mysticism, Currency, Iron Working, 
 Code of Laws, Writing, Map Making, The Wheel, 
 Masonry, Ceremonial Burial, Bronze Working, 
 Alphabet

   -> SS Component, Superconductor, Robotics, 
 Fusion Power, SDI Defence, Artillery, Mfg Plant, 
 SS Module

Superconductor    <- Plastic, Space Flight, Rocketry, Advanced Flight, 
 Mass Production, Flight, Automobile, Combustion, 
 Refining, Computers, Corporation, Steel, 
 Electronics, Industrialization, Electricity, 
 Railroad, Metallurgy, Explosives, Steam Engine, 
 Magnetism, Gunpowder, Chemistry, Physics, Invention, 
 University, Medicine, Banking, Navigation, 
 Bridge Building, Engineering, Philosophy, Republic, 
 Astronomy, Construction, Trade, Literacy, 
 Mathematics, Mysticism, Currency, Iron Working, 
 Code of Laws, Writing, Map Making, The Wheel, 
 Masonry, Ceremonial Burial, Bronze Working, 
 Alphabet

   -> Fusion Power, SDI Defence

Robotics<- Plastic, Space Flight, Rocketry, Advanced Flight, 
 Flight, Combustion, Refining, Computers, 
 Corporation, Electronics, Industrialization, 
 Electricity, Railroad, Metallurgy, Explosives, 
 Steam Engine, Magnetism, Gunpowder, Chemistry, 
 Physics, Invention, University, Medicine, Banking, 
 Navigation, Bridge Building, Engineering, 
 Philosophy, Republic, Astronomy, Construction, 
 Trade, Literacy, Mathematics, Mysticism, Currency, 
 Iron Working, Code of Laws, Writing, Map Making, 
 The Wheel, Masonry, Ceremonial Burial, 
 Bronze Working, Alphabet

   -> Artillery, Mfg Plant, SS Module

Fusion Power <- Superconductor, Plastic, Space Flight, 
 Nuclear Power, Rocketry, Nuclear Fission, 
 Advanced Flight, Mass Production, Flight, 
 Automobile, Combustion, Refining, Computers, 
 Corporation, Steel, Electronics, Industrialization, 
 Electricity, Railroad, Metallurgy, Explosives, 
 Atomic Theory, Steam Engine, Magnetism, Gunpowder, 
 Theory of Gravity, Chemistry, Physics, Invention, 
 University, Medicine, Banking, Navigation, 
 Bridge Building, Engineering, Philosophy, Republic, 
 Astronomy, Construction, Trade, Literacy, 
 Mathematics, Mysticism, Currency, Iron Working, 
 Code of Laws, Writing, Map Making, The Wheel, 
 Masonry, Ceremonial Burial, Bronze Working, 
 Alphabet



IMPROVEMENTS
------------

Temple  <- Ceremonial Burial

Palace  <- Masonry

City Wall    <- Masonry

Granary <- Pottery

Library <- Writing, Alphabet

Courthouse   <- Code of Laws, Alphabet

Marketplace  <- Currency, Bronze Working

Aqueduct<- Construction, Currency, Masonry, Bronze Working

Colosseum    <- Construction, Currency, Masonry, Bronze Working

Fortress<- Construction, Currency, Masonry, Bronze Working

Bank    <- Banking, Republic, Trade, Literacy, Currency, 
 Code of Laws, Writing, Bronze Working, Alphabet

Cathedral    <- Religion, Philosophy, Literacy, Mysticism, 
 Code of Laws, Writing, Ceremonial Burial, Alphabet

University (Imp)  <- University, Philosophy, Literacy, Mathematics, 
 Mysticism, Code of Laws, Writing, Masonry, 
 Ceremonial Burial, Alphabet

Factory <- Industrialization, Railroad, Steam Engine, Physics, 
 Invention, Banking, Navigation, Bridge Building, 
 Engineering, Republic, Astronomy, Construction, 
 Trade, Literacy, Mathematics, Mysticism, Currency, 
 Iron Working, Code of Laws, Writing, Map Making, 
 The Wheel, Masonry, Ceremonial Burial, 
 Bronze Working, Alphabet

Hydro Plant  <- Electronics, Electricity, Metallurgy, Magnetism, 
 Gunpowder, Physics, Invention, University, 
 Navigation, Engineering, Philosophy, Astronomy, 
 Construction, Literacy, Mathematics, Mysticism, 
 Currency, Iron Working, Code of Laws, Writing, 
 Map Making, The Wheel, Masonry, Ceremonial Burial, 
 Bronze Working, Alphabet

Power Plant  <- Refining, Corporation, Industrialization, Railroad, 
 Steam Engine, Chemistry, Physics, Invention, 
 University, Medicine, Banking, Navigation, 
 Bridge Building, Engineering, Philosophy, Republic, 
 Astronomy, Construction, Trade, Literacy, 
 Mathematics, Mysticism, Currency, Iron Working, 
 Code of Laws, Writing, Map Making, The Wheel, 
 Masonry, Ceremonial Burial, Bronze Working, 
 Alphabet

Mass Transit <- Mass Production, Automobile, Combustion, Refining, 
 Corporation, Steel, Industrialization, Railroad, 
 Metallurgy, Explosives, Steam Engine, Gunpowder, 
 Chemistry, Physics, Invention, University, Medicine, 
 Banking, Navigation, Bridge Building, Engineering, 
 Philosophy, Republic, Astronomy, Construction, 
 Trade, Literacy, Mathematics, Mysticism, Currency, 
 Iron Working, Code of Laws, Writing, Map Making, 
 The Wheel, Masonry, Ceremonial Burial, 
 Bronze Working, Alphabet

Recycling Center  <- Recycling, Mass Production, Automobile, Combustion, 
 Refining, Corporation, Steel, Industrialization, 
 Railroad, Metallurgy, Explosives, Steam Engine, 
 Gunpowder, Chemistry, Physics, Invention, 
 University, Democracy, Medicine, Banking, 
 Navigation, Bridge Building, Engineering, 
 Philosophy, Republic, Astronomy, Construction, 
 Trade, Literacy, Mathematics, Mysticism, Currency, 
 Iron Working, Code of Laws, Writing, Map Making, 
 The Wheel, Masonry, Ceremonial Burial, 
 Bronze Working, Alphabet

Nuclear Plant<- Nuclear Power, Nuclear Fission, Mass Production, 
 Automobile, Combustion, Refining, Corporation, 
 Steel, Electronics, Industrialization, Electricity, 
 Railroad, Metallurgy, Explosives, Atomic Theory, 
 Steam Engine, Magnetism, Gunpowder, 
 Theory of Gravity, Chemistry, Physics, Invention, 
 University, Medicine, Banking, Navigation, 
 Bridge Building, Engineering, Philosophy, Republic, 
 Astronomy, Construction, Trade, Literacy, 
 Mathematics, Mysticism, Currency, Iron Working, 
 Code of Laws, Writing, Map Making, The Wheel, 
 Masonry, Ceremonial Burial, Bronze Working, 
 Alphabet

SS Structure <- Space Flight, Rocketry, Advanced Flight, Flight, 
 Combustion, Refining, Computers, Corporation, 
 Electronics, Industrialization, Electricity, 
 Railroad, Metallurgy, Explosives, Steam Engine, 
 Magnetism, Gunpowder, Chemistry, Physics, Invention, 
 University, Medicine, Banking, Navigation, 
 Bridge Building, Engineering, Philosophy, Republic, 
 Astronomy, Construction, Trade, Literacy, 
 Mathematics, Mysticism, Currency, Iron Working, 
 Code of Laws, Writing, Map Making, The Wheel, 
 Masonry, Ceremonial Burial, Bronze Working, 
 Alphabet

SS Component <- Plastic, Space Flight, Rocketry, Advanced Flight, 
 Flight, Combustion, Refining, Computers, 
 Corporation, Electronics, Industrialization, 
 Electricity, Railroad, Metallurgy, Explosives, 
 Steam Engine, Magnetism, Gunpowder, Chemistry, 
 Physics, Invention, University, Medicine, Banking, 
 Navigation, Bridge Building, Engineering, 
 Philosophy, Republic, Astronomy, Construction, 
 Trade, Literacy, Mathematics, Mysticism, Currency, 
 Iron Working, Code of Laws, Writing, Map Making, 
 The Wheel, Masonry, Ceremonial Burial, 
 Bronze Working, Alphabet

SDI Defence  <- Superconductor, Plastic, Space Flight, Rocketry, 
 Advanced Flight, Mass Production, Flight, 
 Automobile, Combustion, Refining, Computers, 
 Corporation, Steel, Electronics, Industrialization, 
 Electricity, Railroad, Metallurgy, Explosives, 
 Steam Engine, Magnetism, Gunpowder, Chemistry, 
 Physics, Invention, University, Medicine, Banking, 
 Navigation, Bridge Building, Engineering, 
 Philosophy, Republic, Astronomy, Construction, 
 Trade, Literacy, Mathematics, Mysticism, Currency, 
 Iron Working, Code of Laws, Writing, Map Making, 
 The Wheel, Masonry, Ceremonial Burial, 
 Bronze Working, Alphabet

Mfg Plant    <- Robotics, Plastic, Space Flight, Rocketry, 
 Advanced Flight, Flight, Combustion, Refining, 
 Computers, Corporation, Electronics, 
 Industrialization, Electricity, Railroad, 
 Metallurgy, Explosives, Steam Engine, Magnetism, 
 Gunpowder, Chemistry, Physics, Invention, 
 University, Medicine, Banking, Navigation, 
 Bridge Building, Engineering, Philosophy, Republic, 
 Astronomy, Construction, Trade, Literacy, 
 Mathematics, Mysticism, Currency, Iron Working, 
 Code of Laws, Writing, Map Making, The Wheel, 
 Masonry, Ceremonial Burial, Bronze Working, 
 Alphabet

SS Module    <- Robotics, Plastic, Space Flight, Rocketry, 
 Advanced Flight, Flight, Combustion, Refining, 
 Computers, Corporation, Electronics, 
 Industrialization, Electricity, Railroad, 
 Metallurgy, Explosives, Steam Engine, Magnetism, 
 Gunpowder, Chemistry, Physics, Invention, 
 University, Medicine, Banking, Navigation, 
 Bridge Building, Engineering, Philosophy, Republic, 
 Astronomy, Construction, Trade, Literacy, 
 Mathematics, Mysticism, Currency, Iron Working, 
 Code of Laws, Writing, Map Making, The Wheel, 
 Masonry, Ceremonial Burial, Bronze Working, 
 Alphabet



WONDERS OF THE WORLD
--------------------

Pyramids<- Masonry

Great Wall   <- Masonry

Hanging Garden    <- Pottery

Lighthouse   <- MapMaking, Alphabet

Oracle  <- Mysticism, Ceremonial Burial

Great Library<- Literacy, Code of Laws, Writing, Alphabet

Copernicus   <- Astronomy, Mathematics, Mysticism, Masonry, 
 Ceremonial Burial, Alphabet

Magellan<- Navigation, Astronomy, Mathematics, Mysticism, 
 Map Making, Masonry, Ceremonial Burial, Alphabet

Shakespeare  <- Medicine, Philosophy, Trade, Literacy, Mysticism, 
 Currency, Code of Laws, Writing, Ceremonial Burial, 
 Bronze Working, Alphabet

J.S. Bach    <- Religion, Philosophy, Literacy, Mysticism, 
 Code of Laws, Writing, Ceremonial Burial, Alphabet

Michelangelo <- Religion, Philosophy, Literacy, Mysticism, 
 Code of Laws, Writing, Ceremonial Burial, Alphabet

Isaac Newton <- Theory of Gravity, University, Philosophy, 
 Astronomy, Literacy, Mathematics, Mysticism, 
 Code of Laws, Writing, Masonry, Ceremonial Burial, 
 Alphabet

Darwin's Voyage   <- Railroad, Steam Engine, Physics, Invention, 
 Navigation, Bridge Building, Engineering, Astronomy, 
 Construction, Literacy, Mathematics, Mysticism, 
 Currency, Iron Working, Code of Laws, Writing, 
 Map Making, The Wheel, Masonry, Ceremonial Burial, 
 Bronze Working, Alphabet

Women's Suffrage  <- Industrialization, Railroad, Steam Engine, Physics, 
 Invention, Banking, Navigation, Bridge Building, 
 Engineering, Republic, Astronomy, Construction, 
 Trade, Literacy, Mathematics, Mysticism, Currency, 
 Iron Working, Code of Laws, Writing, Map Making, 
 The Wheel, Masonry, Ceremonial Burial, 
 Bronze Working, Alphabet

Hoover Dam   <- Electronics, Electricity, Metallurgy, Magnetism, 
 Gunpowder, Physics, Invention, University, 
 Navigation, Engineering, Philosophy, Astronomy, 
 Construction, Literacy, Mathematics, Mysticism, 
 Currency, Iron Working, Code of Laws, Writing, 
 Map Making, The Wheel, Masonry, Ceremonial Burial, 
 Bronze Working, Alphabet

United Nations    <- Communism, Industrialization, Railroad, 
 Steam Engine, Physics, Invention, Banking, 
 Navigation, Bridge Building, Engineering, 
 Philosophy, Republic, Astronomy, Construction, 
 Trade, Literacy, Mathematics, Mysticism, Currency, 
 Iron Working, Code of Laws, Writing, Map Making, 
 The Wheel, Masonry, Ceremonial Burial, 
 Bronze Working, Alphabet

SETI Program <- Computers, Electronics, Electricity, Metallurgy, 
 Magnetism, Gunpowder, Physics, Invention, 
 University, Navigation, Engineering, Philosophy, 
 Astronomy, Construction, Literacy, Mathematics, 
 Mysticism, Currency, Iron Working, Code of Laws, 
 Writing, Map Making, The Wheel, Masonry, 
 Ceremonial Burial, Bronze Working, Alphabet

Cure for Cancer   <- Genetic Eng., Corporation, Industrialization, 
 Railroad, Steam Engine, Physics, Invention, 
 Medicine, Banking, Navigation, Bridge Building, 
 Engineering, Philosophy, Republic, Astronomy, 
 Construction, Trade, Literacy, Mathematics, 
 Mysticism, Currency, Iron Working, Code of Laws, 
 Writing, Map Making, The Wheel, Masonry, 
 Ceremonial Burial, Bronze Working, Alphabet

Manhattan Project <- Nuclear Fission, Mass Production, Automobile, 
 Combustion, Refining, Corporation, Steel, 
 Industrialization, Railroad, Metallurgy, Explosives, 
 Atomic Theory, Steam Engine, Gunpowder, 
 Theory of Gravity, Chemistry, Physics, Invention, 
 University, Medicine, Banking, Navigation, 
 Bridge Building, Engineering, Philosophy, Republic, 
 Astronomy, Construction, Trade, Literacy, 
 Mathematics, Mysticism, Currency, Iron Working, 
 Code of Laws, Writing, Map Making, The Wheel, 
 Masonry, Ceremonial Burial, Bronze Working, 
 Alphabet

Apollo Program    <- Space Flight, Rocketry, Advanced Flight, Flight, 
 Combustion, Refining, Computers, Corporation, 
 Electronics, Industrialization, Electricity, 
 Railroad, Metallurgy, Explosives, Steam Engine, 
 Magnetism, Gunpowder, Chemistry, Physics, Invention, 
 University, Medicine, Banking, Navigation, 
 Bridge Building, Engineering, Philosophy, Republic, 
 Astronomy, Construction, Trade, Literacy, 
 Mathematics, Mysticism, Currency, Iron Working, 
 Code of Laws, Writing, Map Making, The Wheel, 
 Masonry, Ceremonial Burial, Bronze Working, 
 Alphabet



UNITS
-----

Chariot <- The Wheel

Cavalry <- Horseback Riding

Diplomat<- Writing, Alphabet

Trireme <- MapMaking, Alphabet

Legion  <- Iron Working, Bronze Working

Catapult<- Mathematics, Masonry, Alphabet

Caravan <- Trade, Currency, Code of Laws, Bronze Working, 
 Alphabet

Sail    <- Navigation, Astronomy, Mathematics, Mysticism, 
 Map Making, Masonry, Ceremonial Burial, Alphabet

Knight  <- Chivalry, Feudalism, Monarchy, Code of Laws, 
 Horseback Riding, Masonry, Ceremonial Burial, 
 Alphabet

Musketeer    <- Gunpowder, Invention, Engineering, Construction, 
 Literacy, Currency, Iron Working, Code of Laws, 
 Writing, The Wheel, Masonry, Bronze Working, 
 Alphabet

Frigate <- Magnetism, Physics, Navigation, Astronomy, 
 Mathematics, Mysticism, Map Making, Masonry, 
 Ceremonial Burial, Alphabet

Ironclad<- Steam Engine, Physics, Invention, Navigation, 
 Engineering, Astronomy, Construction, Literacy, 
 Mathematics, Mysticism, Currency, Code of Laws, 
 Writing, Map Making, The Wheel, Masonry, 
 Ceremonial Burial, Bronze Working, Alphabet

Cannon  <- Metallurgy, Gunpowder, Invention, University, 
 Engineering, Philosophy, Construction, Literacy, 
 Mathematics, Mysticism, Currency, Iron Working, 
 Code of Laws, Writing, The Wheel, Masonry, 
 Ceremonial Burial, Bronze Working, Alphabet

Rifleman<- Conscription, Explosives, Gunpowder, Chemistry, 
 Invention, University, Medicine, Engineering, 
 Philosophy, Republic, Construction, Trade, Literacy, 
 Mathematics, Mysticism, Currency, Iron Working, 
 Code of Laws, Writing, The Wheel, Masonry, 
 Ceremonial Burial, Bronze Working, Alphabet

Transport    <- Industrialization, Railroad, Steam Engine, Physics, 
 Invention, Banking, Navigation, Bridge Building, 
 Engineering, Republic, Astronomy, Construction, 
 Trade, Literacy, Mathematics, Mysticism, Currency, 
 Iron Working, Code of Laws, Writing, Map Making, 
 The Wheel, Masonry, Ceremonial Burial, 
 Bronze Working, Alphabet

Battleship   <- Steel, Industrialization, Railroad, Metallurgy, 
 Steam Engine, Gunpowder, Physics, Invention, 
 University, Banking, Navigation, Bridge Building, 
 Engineering, Philosophy, Republic, Astronomy, 
 Construction, Trade, Literacy, Mathematics, 
 Mysticism, Currency, Iron Working, Code of Laws, 
 Writing, Map Making, The Wheel, Masonry, 
 Ceremonial Burial, Bronze Working, Alphabet

Cruiser <- Combustion, Refining, Corporation, 
 Industrialization, Railroad, Explosives, 
 Steam Engine, Gunpowder, Chemistry, Physics, 
 Invention, University, Medicine, Banking, 
 Navigation, Bridge Building, Engineering, 
 Philosophy, Republic, Astronomy, Construction, 
 Trade, Literacy, Mathematics, Mysticism, Currency, 
 Iron Working, Code of Laws, Writing, Map Making, 
 The Wheel, Masonry, Ceremonial Burial, 
 Bronze Working, Alphabet

Armor   <- Automobile, Combustion, Refining, Corporation, 
 Steel, Industrialization, Railroad, Metallurgy, 
 Explosives, Steam Engine, Gunpowder, Chemistry, 
 Physics, Invention, University, Medicine, Banking, 
 Navigation, Bridge Building, Engineering, 
 Philosophy, Republic, Astronomy, Construction, 
 Trade, Literacy, Mathematics, Mysticism, Currency, 
 Iron Working, Code of Laws, Writing, Map Making, 
 The Wheel, Masonry, Ceremonial Burial, 
 Bronze Working, Alphabet

Fighter <- Flight, Combustion, Refining, Corporation, 
 Industrialization, Railroad, Explosives, 
 Steam Engine, Gunpowder, Chemistry, Physics, 
 Invention, University, Medicine, Banking, 
 Navigation, Bridge Building, Engineering, 
 Philosophy, Republic, Astronomy, Construction, 
 Trade, Literacy, Mathematics, Mysticism, Currency, 
 Iron Working, Code of Laws, Writing, Map Making, 
 The Wheel, Masonry, Ceremonial Burial, 
 Bronze Working, Alphabet

Submarine    <- Mass Production, Automobile, Combustion, Refining, 
 Corporation, Steel, Industrialization, Railroad, 
 Metallurgy, Explosives, Steam Engine, Gunpowder, 
 Chemistry, Physics, Invention, University, Medicine, 
 Banking, Navigation, Bridge Building, Engineering, 
 Philosophy, Republic, Astronomy, Construction, 
 Trade, Literacy, Mathematics, Mysticism, Currency, 
 Iron Working, Code of Laws, Writing, Map Making, 
 The Wheel, Masonry, Ceremonial Burial, 
 Bronze Working, Alphabet

Bomber  <- Advanced Flight, Flight, Combustion, Refining, 
 Corporation, Industrialization, Electricity, 
 Railroad, Metallurgy, Explosives, Steam Engine, 
 Magnetism, Gunpowder, Chemistry, Physics, Invention, 
 University, Medicine, Banking, Navigation, 
 Bridge Building, Engineering, Philosophy, Republic, 
 Astronomy, Construction, Trade, Literacy, 
 Mathematics, Mysticism, Currency, Iron Working, 
 Code of Laws, Writing, Map Making, The Wheel, 
 Masonry, Ceremonial Burial, Bronze Working, 
 Alphabet

Carrier <- Advanced Flight, Flight, Combustion, Refining, 
 Corporation, Industrialization, Electricity, 
 Railroad, Metallurgy, Explosives, Steam Engine, 
 Magnetism, Gunpowder, Chemistry, Physics, Invention, 
 University, Medicine, Banking, Navigation, 
 Bridge Building, Engineering, Philosophy, Republic, 
 Astronomy, Construction, Trade, Literacy, 
 Mathematics, Mysticism, Currency, Iron Working, 
 Code of Laws, Writing, Map Making, The Wheel, 
 Masonry, Ceremonial Burial, Bronze Working, 
 Alphabet

Mech Infantry<- Labor Union, Mass Production, Automobile, 
 Combustion, Refining, Communism, Corporation, Steel, 
 Industrialization, Railroad, Metallurgy, Explosives, 
 Steam Engine, Gunpowder, Chemistry, Physics, 
 Invention, University, Medicine, Banking, 
 Navigation, Bridge Building, Engineering, 
 Philosophy, Republic, Astronomy, Construction, 
 Trade, Literacy, Mathematics, Mysticism, Currency, 
 Iron Working, Code of Laws, Writing, Map Making, 
 The Wheel, Masonry, Ceremonial Burial, 
 Bronze Working, Alphabet

Nuclear Unit <- Rocketry, Advanced Flight, Flight, Combustion, 
 Refining, Corporation, Electronics, 
 Industrialization, Electricity, Railroad, 
 Metallurgy, Explosives, Steam Engine, Magnetism, 
 Gunpowder, Chemistry, Physics, Invention, 
 University, Medicine, Banking, Navigation, 
 Bridge Building, Engineering, Philosophy, Republic, 
 Astronomy, Construction, Trade, Literacy, 
 Mathematics, Mysticism, Currency, Iron Working, 
 Code of Laws, Writing, Map Making, The Wheel, 
 Masonry, Ceremonial Burial, Bronze Working, 
 Alphabet

Artillery    <- Robotics, Plastic, Space Flight, Rocketry, 
 Advanced Flight, Flight, Combustion, Refining, 
 Computers, Corporation, Electronics, 
 Industrialization, Electricity, Railroad, 
 Metallurgy, Explosives, Steam Engine, Magnetism, 
 Gunpowder, Chemistry, Physics, Invention, 
 University, Medicine, Banking, Navigation, 
 Bridge Building, Engineering, Philosophy, Republic, 
 Astronomy, Construction, Trade, Literacy, 
 Mathematics, Mysticism, Currency, Iron Working, 
 Code of Laws, Writing, Map Making, The Wheel, 
 Masonry, Ceremonial Burial, Bronze Working, 
 Alphabet