Não informado. Statistical and other data on minerals: Quarterly information circular. Republic of South Africa, Department of Mines.
Chicago-Zitierstil (17. Ausg.)Não informado. Statistical and Other Data on Minerals: Quarterly Information Circular. Pretoria, Africa do Sul: Republic of South Africa, Department of Mines.
MLA-Zitierstil (8. Ausg.)Não informado. Statistical and Other Data on Minerals: Quarterly Information Circular. Republic of South Africa, Department of Mines.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.