Não informado. (1956). Journal of the Southern African Institute of Mining and Metallurgy. South African Institute of Mining and Metallurgy.
শিকাগো স্টাইল (17 তম সংস্করণ) উদ্ধৃতিNão informado. Journal of the Southern African Institute of Mining and Metallurgy. Johannesburg, Africa do Sul: South African Institute of Mining and Metallurgy, 1956.
M.L.A (8 ম সংস্করণ) উদ্ধৃতিNão informado. Journal of the Southern African Institute of Mining and Metallurgy. South African Institute of Mining and Metallurgy, 1956.
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