List of sources:
FamilySearch: John Lincoln Watson. https://www.familysearch.org/ark:/61903/3:1:3Q9M-C91P-Z3V6-H?view=index&personArk=/ark:/61903/1:1:ZT6Y-F5PZ&action=view&cc=2721608&lang=en&groupId=M96Z-X8G AND https://www.familysearch.org/en/tree/person/details/LT19-4SD
(The) Kwazulu-Natal Family History Society. Retrieved on 17April 2021 from http://nifhs.co.za/?page_id=825 See Watson, John Lincoln.
Liebenberg, E.C. Die topografiese kartering van Suid-Afrika, 1879-1972; 'n histories-geografiese ontleding. MA-verhandeling in geografie, Universiteit van Suid-Afrika, 1973.
Natal [Colony]. Civil service list, 1906, 1910.
Natal almanac, directory and yearly register, 1909, pp. 53-54, Land surveyors.
Natal who's who, 1906.
National Automated Archival Information Retrieval System (NAAIRS). http://national.archives.gov.za/naairs.htm Documents relating to Watson, John Lincoln / Watson, J.L.
Union of South Africa. Public service list, 1914.