List of sources:
Agricultural Journal (Union of South Africa), 1913, Vol. 5, articles by H.J. Choles.
Google scholar. http://scholar.google.co.za/ Publications by H.J. Choles.
Hall, A.L. A bibliography of South African geology for the years 1921 to 1925. Pretoria: Geological Survey, Memoir No. 25, 1927.
Natal Civil Service List, 1906. Pietermaritzburg: P. Davis & Sons,1906.
National Archives Repository (TAB), Source MHG, Vol. 0, Ref. 7001/51: Death notice, Herbert John Choles.
National Automated Archival Information Retrieval System (NAAIRS), at http://www.national.archives.gov.za/naairs.htm Documents relating to Herbert John Choles / H.J. Choles.
Union of South Africa. Public Service List, 1914. Pretoria: Government Printer, 1914.
University of the Cape of Good Hope. Calendar, 1903/4.