Region
United States --
10
United States
9
Great Britain
4
Great Britain --
4
Germany --
2
Soviet Union
2
United states --
2
20th Century
1
Afghanistan --
1
Africa --
1
Africa, Northeast
1
Asia, Southeastern
1
Asia, Southeastern --
1
Australia
1
Australia --
1
Caucasus, Northern
1
Central America
1
Developing countries
1
Developing countries --
1
East Asia
1
East Asia --
1
Eurasia --
1
Europe --
1
Germany
1
Latin America --
1
Russia(Federation) --
1
Soviet Union --
1
United States - --
1