Region
United States
92
Germany
43
California
8
Developing countries
8
Moon
8
Allemagne
5
Japan
5
Venus (Planet)
5
Massachusetts
4
New England
4
Boston Metropolitan Area
3
Brazil
3
Europe
3
Mexico
3
Soviet Union
3
Chile
2
China
2
Earth (Planet)
2
European Union countries
2
Greece
2
India
2
North Sea
2
Northeastern States
2
Africa
1
Argentina
1
Australia
1
Belgium
1
British Indian Ocean Territory
1
Brussels
1
Cambridge
1
Canada
1
Chestnut Ridge Area
1
Colombia
1
Diego Garcia
1
France
1
Germany (West)
1
Hanford Site (Wash.)
1
Huai River (China)
1
Idaho
1
Illinois
1
Italy
1
La Salle County
1
Los Alamos County
1
Maine
1
Maryland
1
Nebraska
1
New Mexico
1
New York
1
New York (State)
1
North America
1
more ...