Subject Region
United States
38
Europe
8
Middle East
6
Germany
5
Great Britain
5
Egypt
3
Rome
3
Canada
2
China
2
Latin America
2
Mexico
2
Santa Clara Valley (Santa Clara County, Calif.)
2
California
1
Campeche (Mexico : State)
1
Campeche (State)
1
Central America
1
Colombia
1
Communist countries
1
Developing countries
1
Earth (Planet)
1
England
1
France
1
Great Lakes Region (North America)
1
Greece
1
Huron, Lake (Mich. and Ont.)
1
Iberian Peninsula
1
Pennsylvania
1
Rockdale (Pa.)
1
Rusia
1
Russia
1
Santa Clara Valley (Santa Clara County)
1
Sri Lanka
1
Tanzania
1
Yucatán Peninsula
1