Não informado. (1960). Information Circular. University of the Witwatersrand, Economic Geology Research Unit.
Chicagoスタイル(17版)引用形式Não informado. Information Circular. Johannesburg, Africa do Sul: University of the Witwatersrand, Economic Geology Research Unit, 1960.
MLA(8版)引用形式Não informado. Information Circular. University of the Witwatersrand, Economic Geology Research Unit, 1960.
警告: この引用は必ずしも正確ではありません.