List of sources:
The botanist who made boxes. South African Journal of Science, 1998, Vol. 94, pp. 47-48.
Dictionary of South African biography, Vol. 2, 1972.
Ffolliott, P. & Liversidge, R. Clemenz Heinrich Wehdemann, naturalist, 1762-1835. Quarterly Bulletin of the South African Library, 1962, Vol. 16(4), pp. 147-160.
Ffolliott, P. & Liversidge, R. Ludwig Krebs, Cape naturalist to the King of Prussia, 1820-1828. Cape Town: Balkema, 1971.
Gunn, M. & Codd, L.E. Botanical exploration of southern Africa. Cape Town: Balkema, 1981.
Hutchinson, J. A botanist in southern Africa. London: Gawthorn, 1946.
Kirby, P.R. Early professional museum collectors in South Africa. Southern African Museums Association Bulletin (SAMAB), 1942, Vol. 2, pp. 393-401.
Transvaal Museum. Annual report, 1905/6. (National Archives, Pretoria, Vol. TKP 196).