List of sources:
Cape of Good Hope. Report of the commissioners appointed for the purpose of determining the unit of land measure within the Colony... (Parliamentary Report G1-'59). Cape Town: Saul Solomon, 1859.
Dictionary of South African biography, Vol. 5, 1987.
Forbes, V. Cloppenburg's journey, 1768. Africana Notes and News, 1962, Vol. 15, pp. 113-123.
Forbes, V. Some early maps of South Africa. Journal for Geography, 1965, Vol. 2(6), pp. 9-20.
Godee Molsbergen, E.C. Reizen in Zuid-Afrika in de Hollandsche Tijd (Vol. 1, pp. 24-50). Den Haag: Linschoten Vereniging, 4 vols, 1916-1932.
Hoge, J. Personalia of the Germans at the Cape, 1652-1806. Archives Yearbook for South African History, 9th year. Cape Town: Government Printer, 1946.
Koeman, C. Nieuwe bijdragen tot de kennis van Zuid-Afrika's historische kartografie. Tijdschrift van het Koningklijk Nederlandsch Aardrijkskundig Genootschap, 1952, Vol. 69, pp. 73-95.
Martin, C.G.C. & Friedlaender, K.J. (eds). History of surveying and land tenure in South Africa: collected papers (pp. 67, 166-168). Cape Town: University of Cape Town, Department of Surveying, 1984.
Moritz, E. Die Deutschen am Kap unter den Hollandischen Herrschaft, 1652-1806 (pp. 265-266). Weimar: H. Bohlaus, 1938.
Mossop, E.E. The journals of Brink and Rhenius. Cape Town: Van Riebeeck Society, 1947.
South African bibliography to the year 1925. London: Mansell, 1979.