List of sources:
Murray, B.K. Wits, the early years. A history of the University of the Witwatersrand, Johannesburg, and its precursors, 1896-1939. Johannesburg: Witwatersrand University Press, 1982.
National Archives Repository (TAB), Source MHG, Vol. 0, Ref. 9998/65: Death notice, last will and testament, Charles John Marc Constancon.
National Automated Archival Information Retrieval System (NAAIRS), at http://www.national.archives.gov.za/naairs.htm Documents relating to Charles John Marc Constancon.
South African Association for the Advancement of Science. Report, 1918, list of members.
South African Institute of Electrical Engineers. Index of SAIEE Transactions, 1909-2007. Electronic file received from SAIEE.