List of sources:
Bauer, A.M. Early German herpetological observations and explorations in southern Africa, with special reference to the Zoological Museum of Berlin. Bonner zoologische Beitraege, 2003, Vol. 52, pp. 193-214.
Bullock, A.A. Bibliography of South African botany (up to 1951). Pretoria: Department of Agricultural Technical Services, 1978.
Chamisso, Adalbert von. Encyclopaedia Britannica, 9th ed., Vol. 5, 1876, pp. 383-384.
Gunn, M. & Codd, L.E. Botanical exploration of southern Africa. Cape Town: Balkema, 1981.
Hutchinson, J. A botanist in southern Africa (pp. 579, 581). London: Gawthorn, 1946.
National Union Catalogue, pre-1956 imprints. London: Mansell, 1968-1980.
Webster's Biographical Dictionary. Springfield: Merriam, 1943, 1960.