Não informado. (1946). Mining Survey. Transvaal and Orange Free State Chamber of Mines.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रNão informado. Mining Survey. Johannesburg, Africa do Sul: Transvaal and Orange Free State Chamber of Mines, 1946.
एमएलए (8वां संस्करण) प्रशस्ति पत्रNão informado. Mining Survey. Transvaal and Orange Free State Chamber of Mines, 1946.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.