Não informado. (1956). Journal of the Southern African Institute of Mining and Metallurgy. South African Institute of Mining and Metallurgy.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Journal of the Southern African Institute of Mining and Metallurgy. Johannesburg, Africa do Sul: South African Institute of Mining and Metallurgy, 1956.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Journal of the Southern African Institute of Mining and Metallurgy. South African Institute of Mining and Metallurgy, 1956.
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