List of sources:
Benson, R.P. Organized medicine in the Eastern Cape. South African Medical Journal, 1981, Vol. 60(16), pp. 631-638.
Burrows, E.H. A history of medicine in South Africa up to the end of the nineteenth century. Cape Town: Balkema, 1958.
Cape of Good Hope. Civil service list, 1896, 1908.
Dubow, S. Illicit union: Scientific racism in modern South Africa (p. 201). Johannesburg: Witwatersrand University Press, 1995.
E.P. Magazine, 1895, Vol. 2(4), pp. 159-160, "Eastern Province Literary and Scientific Society"; Vol. 2(5), pp. 214-215: "Proceedings of the society".
FamilySearch: Thomas Duncan Greenlees https://www.familysearch.org/tree/person/details/9MWK-V92
Grahamstown Journal, 26, 28 and 31 May 1892, p. 3: "The brain".
Greenlees, T.D. The relation of genius to insanity. E.P. Magazine, 1895, Vol. 2(5), pp. 161-183.
Medical and pharmacy register for the Colony of the Cape of Good Hope, 1893, 1907.
National Automated Archival Information Retrieval System (NAAIRS). http://www.national.archives.gov.za/naairs.htm Documents relating to Greenlees, T. Duncan/Greenlees, T.D./Greenlees, J.D/Greenlees, Dr.
Obituary: Thomas Duncan
Greenlees. British Medical Journal, 9
February 1929, p. 272. Downloaded from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2449971/?page=1
on 14 March 2017.
South African Association for the Advancement of Science. Report, 1903, list of members.
South African bibliography to the year 1925. London: Mansell, 1979.
South African medical directory for 1897. Cape Town: Cape Times, 1897.
South African Medical Journal, 2nd series, 1896, Vol. 4, p. 100, "Meetings of societies; 1898, Vol. 5, pp. 240-242: "South African Medical Association"; pp. 279-280, "Meetings of societies".