Não informado. (2021). Annual Report of the Geological Survey and Mines Department, Bechuanaland. Geological Survey and Mines Department.
Citação do estilo Chicago (17ª ed.)Não informado. Annual Report of the Geological Survey and Mines Department, Bechuanaland. Gaberones: Geological Survey and Mines Department, 2021.
Citação MLA (8ª ed.)Não informado. Annual Report of the Geological Survey and Mines Department, Bechuanaland. Geological Survey and Mines Department, 2021.
警告：这些引文格式不一定是100％准确.