- Karibib Townlands Farm 57
| Roering, C. & Heckroodt, R. O. (1966): The alteration of beryl in the Dernburg pegmatite, Karibib, South West Africa. Annals of the Geological Survey, Republic of South Africa (Annale van die Geologiese Opname, Republiek van Suid-Afrika) 3, 133-137. |