Não informado. (2021). Annual Report of the Geological Survey and Mines Department, Bechuanaland. Geological Survey and Mines Department.
Chicago-referens (17:e uppl.)Não informado. Annual Report of the Geological Survey and Mines Department, Bechuanaland. Gaberones: Geological Survey and Mines Department, 2021.
MLA-referens (8:e uppl.)Não informado. Annual Report of the Geological Survey and Mines Department, Bechuanaland. Geological Survey and Mines Department, 2021.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.