Não informado. (1963). Annual Research Review. Chamber of Mines of South Africa.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रNão informado. Annual Research Review. Johannesburg, Africa do Sul: Chamber of Mines of South Africa, 1963.
एमएलए (8वां संस्करण) प्रशस्ति पत्रNão informado. Annual Research Review. Chamber of Mines of South Africa, 1963.
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