Não informado. (2020). Report of the Geological Survey of Natal and Zululand. P. Davis & Sons, Printers.
Chicago-referens (17:e uppl.)Não informado. Report of the Geological Survey of Natal and Zululand. Pietermaritzburg, Africa do Sul: P. Davis & Sons, Printers, 2020.
MLA-referens (8:e uppl.)Não informado. Report of the Geological Survey of Natal and Zululand. P. Davis & Sons, Printers, 2020.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.