Region
- Afghanistan 1 results
- Africa 2 results
- Africa, Southern 1 results
- Africa, Sub-Saharan 4 results
- Africa, West 1 results
- Alabama 2 results
- Alaska 1 results
- Alberta 1 results
- America 2 results
- Amérique du Nord 1 results
- Aral Sea Region (Uzbekistan and Kazakstan) 1 results
- Arctic National Wildlife Refuge (Alaska) 1 results
- Asia 4 results
- Asia (Roman province) 1 results
- Asia, Central 1 results
- Australia 3 results
- Azov, Sea of (Ukraine and Russia) 1 results
- Beaumont 1 results
- Black Sea 1 results
- Bohemia 1 results
- Boston Harbor 1 results
- British Columbia 2 results
- Burma 1 results
- California 5 results
- Cambodia 2 results
- Canada 14 results
- Canada, Western 1 results
- Cave Rock (Nev.) 1 results
- Central Valley 1 results
- China 8 results
- Clarendon County 1 results
- Colombie-Britannique 1 results
- Colorado 1 results
- Columbia River Watershed 1 results
- Confederate States of America 1 results
- Cuba 1 results
- Czech Republic 2 results
- Darfur 1 results
- Denmark 1 results
- Developing countries 10 results
- Egypt 1 results
- England 6 results
- Estonia 1 results
- Euphrates River Watershed 1 results
- Europe 29 results
- Europe, Eastern 1 results
- Europe, Northern 1 results
- Europe, Western 1 results
- European Economic Community countries 2 results
- European Union countries 45 results more…