Não informado. (1964). Coal, gold and base minerals of Southern Africa. Pithead Press.
Chicago-referens (17:e uppl.)Não informado. Coal, Gold and Base Minerals of Southern Africa. Johannesburg, Africa do Sul: Pithead Press, 1964.
MLA-referens (8:e uppl.)Não informado. Coal, Gold and Base Minerals of Southern Africa. Pithead Press, 1964.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.