List of sources:
Barberton Scientific and Literary Society. Proceedings, 8th and 9th meetings, July and August 1889.
Douglas Flemmer
Gilfillan. http://www.1820settlers.com/genealogy/getperson.php?personID=I9949&tree=master
Downloaded 2018-1-4.
Gilliland, H.B. On the history of plant study upon the Witwatersrand. Journal of South African botany, 1953, Vol. 19, pp. 93-104.
Gunn, M. & Codd, L.E. Botanical exploration of southern Africa. Cape Town: Balkema, 1981.
Heese, J.A. South African genealogies. Pretoria and Stellenbosch, 1986-2005.
Journal of the South African Ornithologists' Union, 1908-1909, Vol. 4-5.
Men of the times: Pioneers of the Transvaal and glimpses of South Africa. Johannesburg: Transvaal Publishing Co., 1905.
National Archives, Pretoria. Source MHG, Volume 0, Reference 4488/48. Death notice, Douglas Flemmer Gilfillan.
National Automated Archival Information Retrieval System (NAAIRS). http://www.national.archives.gov.za/naairs.htm Documents relating to Gilfillan, Douglas Flemmer / Gilfillan, D.F.
Personal communication from Craig Hilton-Taylor, Manager of Red List Unit, IUCN, Cambridge, United Kingdom, 2009-8-31.
South African Journal of Natural History, 1920, Vol. 2(2), pp. 293-301, Roll of members of the SA Biological Society.
South African who's who, 1908, 1919/1920, 1947/8.
University of the Cape of Good Hope. Calendar, 1887/8