Não informado. South West Africa series. Geological Survey of South Africa.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. South West Africa Series. Pretoria, Africa do Sul: Geological Survey of South Africa.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. South West Africa Series. Geological Survey of South Africa.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.