Region
United States
Great Britain
7
Japan
4
Soviet Union
4
California, Northern
3
Massachusetts
3
China
2
England
2
France
2
United states
2
Africa
1
Canada
1
Economic aspects
1
Europe
1
Germany
1
Germany (Federal Republic, 1949- )
1
Greece
1
Iraq
1
Latin America
1
Poland
1
Rome
1
Russia
1
Saint Louis (Mo.)
1
South Africa
1
USA
1
United State
1
West Indies
1
West Indies, British
1