Geographic Subject
Germany
100
France
55
Switzerland
53
Sweden
49
Germany (West)
25
Netherlands
14
Great Britain
13
United States
10
Romania
9
Hungary
8
Iran
8
Algeria
7
China
7
Finland
7
India
7
Indonesia
7
Denmark
6
Developing countries
6
Kenya
6
Mexico
6
Spain
6
Ethiopia
5
Silesia
5
Tanzania
5
Baden
4
Colombia
4
Egypt
4
Japan
4
Morocco
4
Turkey
4
4.210
3
Bavaria
3
Botswana
3
Brazil
3
Bulgaria
3
Cameroon
3
Ecuador
3
European Economic Community countries
3
Germany (East)
3
Greece
3
Italy
3
Korea (South)
3
Lower Saxony
3
North Rhine-Westphalia
3
Poland
3
Prussia
3
Senegal
3
South Africa
3
Soviet Union
3
Tunisia
3
more ...