Region
Africa
3
Alaska
1
Antarctica
1
Asia
3
Australia
7
Books and reading
1
California
3
Canada
4
Central America
1
China
5
Ciudad Juárez
1
Detroit
1
Earth (Planet)
1
Education (Elementary)
1
Education (Secondary)
1
Egypt
1
El Paso
1
England
2
English-speaking countries
1
Europe
4
France
1
Germany
1
Gettysburg National Military Park (Pa.)
1
Great Britain
53
Greece
3
Hiroshima-shi
1
Hunters Point (San Francisco, Calif.)
1
India
2
Iraq
1
Israel
1
Japan
5
Jimmy Carter National Historic Site (Plains, Ga.)
1
Kenya
1
Kuwait
1
Mars (Planet)
1
Media
1
Mexico
4
Michigan
3
Missouri
1
Netherlands
1
New York
2
New York (State)
2
Nigeria
1
North America
3
North Dakota
1
Pennsylvania
1
Poland
1
Rome
3
Russia
2
San Francisco
1
more ...