Não informado. World cartography. United Nations, Department of Social Affairs.
Chicago-referens (17:e uppl.)Não informado. World Cartography. New York: United Nations, Department of Social Affairs.
MLA-referens (8:e uppl.)Não informado. World Cartography. United Nations, Department of Social Affairs.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.