1. Spacial Organization: The Geographers's View of the World;Abler,1972
2. Ecumenopolis: The Inevitable City of the Future;Doxiadis;Atene,1974
3. The Rise and Fall of Infrastructures;Grübler,1989
4. Historical Statistics on the U.S. Colonial Times to 1970;U.S. Department of Commerce,1975