List of sources:
Cape of Good Hope. Civil service list, 1885, 1886, 1887, 1888, 1890.
Cape of Good Hope. Report of the Conservators of Forests (title varies), 1863-1883; and Report of the Superintendent of Woods and Forests, 1884-1890.
Dictionary of South African biography, Vol. 3, 1977.
FamilySearch: Christopher Harison. https://www.familysearch.org/ark:/61903/3:1:3Q9M-CSQ8-4SJB-Z?view=index&personArk=/ark:/61903/1:1:QGTQ-6MJR&action=view&cc=2517051 AND https://www.familysearch.org/tree/person/details/GMX1-VF6
Heese, J.A. South African genealogies. Pretoria and Stellenbosch, 1986-2008.
Keet, J.D.M. Historical review of the development of forestry in South Africa, c. 1972. Digital copy received from Forestry Scientific/Technical Services, Knysna.
Lister, M.H. Joseph Storr Lister, the first Chief Conservator of the South African Department of Forestry. Journal of the South African Forestry Association, 1957, No. 29, pp. 10-18.
National Automated Archival Information Retrieval System (NAAIRS). http://www.national.archives.gov.za/naairs.htm Documents relating to Harison, Christopher.
Standard Encyclopaedia of Southern Africa (SESA). Cape Town: NASOU, 1970-1976.