Subject Region
United States
239
Great Britain
95
Soviet Union
93
Germany
39
China
16
Israel
14
France
13
Communist countries
12
Middle East
9
New York (State)
9
Cuba
8
Russia
8
Europe
7
Afghanistan
6
England
6
Ireland
6
New York
6
Australia
5
Berlin
5
Canada
5
Egypt
5
Russia (Federation)
5
Berlin (Germany)
4
Germany (East)
4
Islamic countries
4
Switzerland
4
Europe, Eastern
3
Latin America
3
Mexico
3
New Mexico
3
Pennsylvania
3
Philadelphia
3
Philippines
3
Poland
3
Spain
3
Tibet Autonomous Region
3
Tibet Autonomous Region (China)
3
Zelenograd (Russia)
3
Austria
2
Belarus
2
Brazil
2
Chile
2
Congo (Democratic Republic)
2
Czechoslovakia
2
El Paso County
2
Florida
2
Germany (West)
2
Hong Kong
2
Iran
2
Japan
2
more ...