Region
United States
10
Mexico
7
México
7
Canada
3
Argentina
2
Great Britain
2
Poland
2
Colombia
1
Developing countries
1
Ingeniería civil
1
Lithuania
1
Michigan
1
Middle West
1
Minnesota
1
New England
1
Rocky Mountains Region
1
Southern Cone of South America
1
Southern States
1
Spain
1
Texas
1
Wisconsin
1