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Dictionary of South African biography, Vol. 1, 1968.
FamilySearch: Willem Frederik Hertzog. https://www.familysearch.org/tree/person/details/KHBC-6TM AND https://www.familysearch.org/ark:/61903/3:1:3Q9M-CSQX-MSJS-Z?view=index&personArk=/ark:/61903/1:1:QGRK-FNM3&action=view&cc=2517051
National Automated Archival Information Retrieval System (NAAIRS). http://www.national.archives.gov.za/naairs.htm Documents relating to Willem Frederik Hertzog / W.F. Hertzog.
Raper, P.E. Dictionary of South African plachttps://www.familysearch.org/tree/person/details/KHBC-6TMe names. Johannesburg: Lowry, 1987.
Ritchie, W. The history of the South African College, 1829-1918. Cape Town: T. Maskew Miller, 1918.
Rogers, A.W. The pioneers in South African geology and their work. Transactions of the Geological Society of South Africa, 1937, Annexure to Vol. 39, pp. 1-139.
Simons, P.B. The life and work of Charles Bell. Vlaeberg: Fernwood Press, 1998.
Smit, J.J. Die paaie, passe en rivieroorgange in Suid-Kaapland, 1806-1858 (p. 119). D.Lit. et Phil. proefskrif in Geskiedenis, Universiteit van Suid-Afrika, 1975.
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Visagie, J.C. 'n Unieke kaart en 'n presiese kartograaf van 150 jaar gelede. South African Survey Journal, 1967, Vol. 11(2), pp. 20-23.