Não informado. (1957). Bibliography and Subject Index of South African Geology. Geological Survey of South Africa.
শিকাগো স্টাইল (17 তম সংস্করণ) উদ্ধৃতিNão informado. Bibliography and Subject Index of South African Geology. Pretoria, Africa do Sul: Geological Survey of South Africa, 1957.
M.L.A (8 ম সংস্করণ) উদ্ধৃতিNão informado. Bibliography and Subject Index of South African Geology. Geological Survey of South Africa, 1957.
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