Region
Soviet Union
Russia
11
United States
9
Russia (Federation)
7
Europe
3
Ukraine
3
Caucasus Region
1
China
1
Developing countries
1
Europe, Eastern
1
Europe, Western
1
Foreign countries
1
Germany
1
Germany (East)
1
Great Britain
1
Kiev
1
Kiev (Ukraine)
1
Leningrad
1
Ozersk (Cheliabinskaia oblast)
1
Ozersk (Cheliabinskaia oblast, Russia)
1
Richland
1
Richland (Wash.)
1
Saint Petersburg (Russia)
1
South Asia
1
Spain
1
Washington (State)
1