Subject Region
United States
Great Britain
73
European Union countries
42
Canada
41
California
30
Washington (D.C.)
26
Europe
24
New York (State)
22
Southern States
21
Germany
18
Pennsylvania
17
Massachusetts
15
New York
12
Michigan
11
Louisiana
10
Australia
9
France
9
Mexico
8
America
7
England
7
Illinois
7
Netherlands
7
Oregon
7
European Economic Community countries
6
Georgia
6
India
6
Missouri
6
South Carolina
6
Belgium
5
Chicago
5
Estados Unidos
5
Iowa
5
Maryland
5
Mississippi
5
New Jersey
5
Virginia
5
Africa
4
Ann Arbor
4
Atlanta
4
China
4
Colorado
4
Connecticut
4
Cuba
4
Hudson River (N.Y. and N.J.)
4
Italy
4
Japan
4
Los Angeles
4
Middle East
4
North America
4
North Carolina
4
more ...