List of sources:
Brookes, E.H. A history of the University of Natal. Pietermaritzburg: University of Natal Press, 1966.
National Automated Archival Information Retrieval System (NAAIRS), at http://www.national.archives.gov.za/naairs.htm Documents relating to Hugh Clark.
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 Institute of Electrical Engineers. Index of SAIEE Transactions, 1909-2007. Electronic file received from SAIEE.
South African Journal of Science, 1932, Vol. 29, papers by Clark; 1937, Vol. 34, pp. xiv-xix, Presidents and secretaries of the sections.
KwaZulu-Natal. Electrical, Electronic and Computer Engineering. School of
Engineering history. http://www.ee.ukzn.ac.za/About-us/History.aspx