List of sources:
Ancestry.com, at http://freepages.genealogy.rootsweb.ancestry.com/~haslatter/history/slatters/OxfordSlatters/bk/f228.htm
as on 18 October 2016.
Cape of Good Hope. Report of the Surveyor-General, 1893.
General Directory of South Africa...(Grahamstown). 1916
Hall, A.D. A bibliography of South African geology to the end of 1920. Pretoria: Geological Survey, Memoir No. 18, 1922.
Institute of Land Surveyors of the Transvaal. Journal, 1905, Vol. 1(1), pp. 24-27; 1909, Vol. 1(8), pp. 338-341: Lists of members.
National Automated Archival Information Retrieval System (NAAIRS). http://www.national.archives.gov.za/naairs.htm Documents relating to Espin, William Mallan/Espin, W.M.
South African who's who, 1917/18.
Transvaal Colony. Civil Service List, 1906, pp. 146-147: List of land surveyors.
University of the Cape of Good Hope. Calendar, 1887/8, 1893/4, 1913/4.
William Mallam Espin. The
Albany graveyard research project. http://www.albany1820.com/transcriptions/Data/Other/Albany Graveyard Research Project/E.htm
as on 19 October 2016.