List of sources:
Beolens, B., Watkins, M. & Grayson, M. The eponym dictionary of reptiles. Baltimore: Johns Hopkins University Press, 2011.
Dictionary of South African biography, Vol. 5, 1987.
Dippenaar, N.J. (Ed.) Staatsmuseum 100. Pretoria, 1992.
FamilySearch: Herman Gottfried Breyer. https://www.familysearch.org/ark:/61903/1:1:QGT5-JSN8
Gunn, M. & Codd, L.E. Botanical exploration of southern Africa. Cape Town: Balkema, 1981.
Gunning, J.W.B. A short history of the Transvaal Museum. Annals of the Transvaal Museum, 1908, Vol. 1(1), pp. 1-13.
[Haagner, A. et al]. The Transvaal Biological Society. South African Journal of Natural History, 1918, Vol. 1(1), pp. 24-32.
Janse, A.J.T. A short history of the South African Biological Society. South African Biological Society Pamphlets, No. 10, 1939, pp. 49-58.
National Automated Archival Information Retrieval System (NAAIRS). http://www.national.archives.gov.za/naairs.htm Documents relating to Herman Gottfried Breyer / H.G. Breyer.
National Union Catalogue, pre-1956 imprints. London: Mansell, 1968-1980.
South African Association for the Advancement of Science. Report, 1918, list of members.
South African Journal of Natural History, 1918, Vol. 1(1), pp. 7-15: Council 1917, and Roll of Foundation Members [of the SA Biological Society].
South African Philosophical Society. Transactions, 1898-1900, Vol. 10, 11: Lists of members.
Staats-Almanak der Zuid-Afrikaansche Republiek, 1896, p. 92, 103; 1897, p. 67; 1898, p. 70.
Transvaal Museum. Annals, 1915-1917, Vol. 5, papers by Breyer.
University of the Cape of Good Hope. Calendar, 1910/1-1917/8.