List of sources:
Cape of Good Hope almanac and annual register (title varies), 1837-1844, 1846, 1856: Cape of Good Hope Agricultural Society.
Dictionary of South African biography, Vol. 3, 1977: Jacob van Reenen (1755-1806).
FamilySearch: Jacob van Reenen. https://ancestors.familysearch.org/en/K4JT-MBL/jacob-van-reenen-1784-1874
Draper, D. Catalogue of the "Rupert Jones" collection of papers and manuscripts. Transactions of the Geological Society of South Africa, 1898, Vol. 4, p. 77-86.
Heese, J.A. South African genealogies. Pretoria and Stellenbosch, 1986-2005.
South African Commercial Advertiser, 30 November 1831, p. 1, Agricultural Society; 7 April 1832, p. 2, Rules and regulations of the Cape of Good Hope Agricultural Society; 1 April 1837, p. 2, Agricultural Society; 1 April 1840, pp. 2-3, Cape of Good Hope Agricultural Society; 21 August 1847, p. 4, Cape of Good Hope Agricultural Society; 11 September 1847, p. 3, Caledon Agricultural Society; 25 September 1847, p. 2, Cape Town - agriculture; 22 September 1852, p. 4, Agricultural Society.