List of sources:
Cape Society of Civil Engineers. Minutes of Proceedings, 1903-1907, Vol. 1-5; 1909-1910, Vol. 7-8.
Men of the times: Old colonists of the Cape Colony and Orange River Colony. Johannesburg: Transvaal Publishing Co., 1906.
Murray, B.K. Wits, the early years. Johannesburg: Witwatersrand University Press, 1982.
National Archives Repository, Pretoria (TAB). Source MHG, Reference 57894. Estate documents, Robert Hearn Charters.
National Automated Archival Information Retrieval System (NAAIRS). http://www.national.archives.gov.za/naairs.htm Documents relating to Charters, Robert Hearn / Charters, R.H.
South African Association for the Advancement of Science. Report, 1918, list of members.
South African bibliography to the year 1925. London: Mansell, 1979.
South African Society of Civil Engineers. Minutes of Proceedings, 1913, Vol. 11, Members.
University of the Cape of Good Hope. Calendar, 1913-1914 and 1914-1915, Colleges.