Não informado. Statistical and other data on minerals: Quarterly information circular. Republic of South Africa, Department of Mines.
Lua i Stíl Chicago (17ú heag.)Não informado. Statistical and Other Data on Minerals: Quarterly Information Circular. Pretoria, Africa do Sul: Republic of South Africa, Department of Mines.
Lua MLA (8ú heag.)Não informado. Statistical and Other Data on Minerals: Quarterly Information Circular. Republic of South Africa, Department of Mines.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.