List of sources:
Chemical and Metallurgical Society of South Africa. Proceedings, 1894-1897, Vol. 1, Fletchers' paper.
Chemical, Metallurgical and Mining Society of South Africa. Journal, 1940, Vol. 41(1), list of office bearers.
National Archives, Pretoria (TAB). Source MHG, Vol. 0, Ref 614/51. Death notice, death certificate and estate papers of Harold Clarkson Fletcher.
National Automated Archival Information Retrieval System (NAAIRS). http://www.national.archives.gov.za/naairs.htm Documents relating to Harold Clarkson Fletcher.
National Union Catalogue, pre-1956 imprints. London: Mansell, 1968-1980.
Rhodesia Scientific Association. Proceedings, 1906, Vol. 6(1); 1918, Vol. 16(2) and 1931, Vol. 30: Lists of members.
South African Association of Engineers and Architects. Proceedings, 1898, Vol. 4, list of members.
South African who's who, 1908, 1919/20, 1923/4, 1944.