Region
- Great Britain 4 Treffer
- United States 3 Treffer
- Bulgaria 2 Treffer
- France 2 Treffer
- Africa, North 1 Treffer
- Colombia 1 Treffer
- Developing countries 1 Treffer
- English-speaking countries 1 Treffer
- Greece 1 Treffer
- Ireland 1 Treffer
- Keweenaw Peninsula (Mich.) 1 Treffer
- Michigan 1 Treffer
- Poland 1 Treffer
- Rome 1 Treffer
- Russia 1 Treffer
- Russia (Federation) 1 Treffer
- Soviet Union 1 Treffer
- Wales 1 Treffer