List of sources:
FamilySearch: John Pratt-Johnson. https://www.familysearch.org/ark:/61903/1:1:QPHQ-5Y1P?lang=en
Google Scholar, at http://scholar.google.co.za Publications by J. Pratt-Johnson.
Medical, dental and
pharmacy directory of South Africa, 1926/7. Johannesburg: Ewald Herbert,
1926.
Medical Journal of
South Africa, 1924/5, Vol. 20, paper by Pratt-Johnson.
National Archives Repository (TAB), Source MHG, Vol. 0, Ref.
2680/60. Death notice: John Pratt-Johnson.
National Automated Archival Information Retrieval System
(NAAIRS), at http://www.national.archives.gov.za/naairs.htm Documents relating to J. Pratt-Johnson / Dr
Pratt-Johnson.
Pietermaritzburg Archives Repository, Vol. NMC 34, List of
medical practitioners, dentists, chemists and druggists, midwives, and nurses
[registered in the Transvaal, as on 31 December 1914].
South African
bibliography to the year 1925. London: Mansell, 1979.
South African Journal
of Science, 1928, Vol. 25, paper by Pratt-Johnson.
Watermeyer, G.A. & Hoffenberg, S.N. Witwatersrand mining practice (reference, p. 687). Johannesburg:
Transvaal Chamber of Mines, 1932.