Geographic Subject
Soviet Union
340
Russia (Federation)
98
United States
57
Europe, Eastern
34
Siberia
32
India
29
Japan
25
Developing countries
23
Africa
18
China
18
France
18
Great Britain
16
Siberia (Russia)
16
Europe
15
Russia
14
Indonesia
12
Egypt
11
Afghanistan
10
Asia
10
Pakistan
10
Asia, Central
9
Asia, Southeastern
9
Australia
9
Iran
9
Poland
9
Germany
8
Turkey
8
Latin America
7
Mongolia
7
Algeria
6
Communist countries
6
Czechoslovakia
6
Oceania
6
Africa, North
5
Korea
5
Moscow (Russia)
5
Siberia, Western
5
Spain
5
Vietnam
5
Vietnam (Democratic Republic)
5
Africa, Sub-Saharan
4
Bashkortostan
4
Brazil
4
Burma
4
Canada
4
Cuba
4
Germany (East)
4
Germany (West)
4
Italy
4
Korea (North)
4
more ...