APA (7e ed.) Bronvermelding

Não informado. (1960). Information Circular. University of the Witwatersrand, Economic Geology Research Unit.

Chicago (17e ed.) Bronvermelding

Não informado. Information Circular. Johannesburg, Africa do Sul: University of the Witwatersrand, Economic Geology Research Unit, 1960.

MLA (8e ed.) Bronvermelding

Não informado. Information Circular. University of the Witwatersrand, Economic Geology Research Unit, 1960.

Let op: Deze citaties zijn niet altijd 100% accuraat.