Subject Region
United States
376
Great Britain
55
Europe
32
Illinois
30
Chicago
29
New York (State)
29
Canada
27
New York
27
England
26
Pennsylvania
26
Mexico
21
China
17
Developing countries
14
Ontario
13
Latin America
12
Spain
12
Chile
11
Espana
11
Japan
11
Netherlands
11
Toronto
11
Colombia
9
Lehigh River Valley
9
London
9
Australia
8
France
8
Soviet Union
8
California
7
Ireland
7
Philadelphia
7
Florida
6
Lehigh County
6
Northampton County
6
Chicago (Ill.)
5
Georgia
5
India
5
Indonesia
5
Ohio
5
South Africa
5
Wales
5
Atlanta
4
Baltimore
4
Brazil
4
Hong Kong
4
Maryland
4
New York (N.Y.)
4
Africa
3
Alberta
3
Amsterdam
3
Argentina
3
more ...