1. From the TEPC Project (Transcription of Estate Papers at the Cape of Good Hope), Universities of the Western Cape and Cape Town, Cape Town Archives Repository, and National Archives at The Hague , www.capetranscripts.co.za : John Fredrik Haszner, 1793, MOOC8/37.32 Johan Ludewich Heller, Christina van de Caab, 5 May 1789, MOOC8/19.50 Jamilla Martha van de Kaap, 8 September 1821, MOOC8/36.8
2. Forbes , V.S 1977 . Anders Sparrman. A voyage to the Cape of Good Hope towards the Antartic polar circle round the world and to the country of the Hottentots and the Caffres from the year 1772–1776 . Based on the English editions of 1785–1786, published by Robinson, London. (Vol. II, Second Series no. 7.) Cape Town : Van Riebeeck Society .
3. Forbes , V.S 1986 . Carl Peter Thunberg at the Cape of Good Hope 1772–1775 . Based on the English editions of 1793–1795, London. (Second Series no. 17.) Cape Town : Van Riebeeck Society .