Subject Region
United States
69
Europe
51
Great Britain
23
Canada
21
Developing countries
20
Germany
16
European Union countries
13
India
12
Latin America
10
China
9
Europe, Western
8
Australia
7
Africa
6
France
6
Japan
6
Mexico
6
New Zealand
6
North America
6
Scandinavia
6
Israel
5
Greece
4
South Africa
4
Soviet Union
4
Syria
4
Ukraine
4
America
3
Asia
3
Asia, Central
3
Central America
3
Egypt
3
Italy
3
Korea (South)
3
Spain
3
Afghanistan
2
Caracas (Venezuela)
2
Communist countries
2
Europe, Eastern
2
Hungary
2
Iran
2
Iraq
2
Mediterranean Region
2
Montevideo (Uruguay)
2
Netherlands
2
Porto Alegre (Rio Grande do Sul, Brazil)
2
Rome
2
Sweden
2
Turkey
2
Arab countries
1
Athens
1
Belgium
1
more ...