Subject Region
United States
30
Great Britain
11
Australia
7
Developing countries
6
Espana
6
Spain
6
England
5
Chile
4
Argentina
3
European Union countries
3
Germany
3
Cameroon
2
Chad Basin Region
2
Western Australia
2
Bahamas
1
Belgium
1
Colombia
1
Europa
1
Europe
1
Former communist countries
1
Italy
1
Japan
1
Union Europea
1
espana
1