United States 157
Michigan 10
Great Britain 5
Europe 4
Developing countries 3
Massachusetts 3
Canada 2
European Economic Community countries 2
France 2
Ireland 2
Africa, Southern 1
Africa, Sub-Saharan 1
California 1
Central America 1
Cyprus 1
Egypt 1
England 1
Ethiopia 1
Europe, Central 1
Europe, Eastern 1
Florida 1
Framingham 1
Hawaii 1
Illinois River (Ill.) 1
India 1
Iran 1
Iraq 1
Japan 1
Jordan 1
Latin America 1
Lebanon 1
Maine 1
Mexico 1
Mississippi River Valley 1
Netherlands 1
New York (N.Y.) 1
OECD countries 1
Ohio River Valley 1
Oregon 1
Scotland 1
Southern States 1
Soviet Union 1
Sudan 1
Syria 1
Turkey 1
Wales 1
West (U.S.) 1