List of sources:
Koeman, C. Nieuwe bijdragen tot de kennis van Zuid-Afrika's historische kartografie. Tijdschrift van het Koninklijk Nederlandsch Aardrijkskundig Genootschap, 1952, Vol. 69, 73-95. An Afrikaans translation was published in C.G.C. Martin and K.J. Friedlaender (eds), History of surveying and land tenure in South Africa: Collected papers. Vol. 1: Surveying and land tenure in the Cape, 1652-1812 (pp. 235-250). Cape Town: University of Cape Town, Department of Surveying, Committee for the History of Surveying and Land Tenure in South Africa, 1984.