List of sources:
Barberton Herald, 29 June 1888, and 10 January 1890: The Barberton Scientific and Literary Society.
Barberton Scientific and Literary Society. Proceedings, 9 July 1888, p. 8; 30 July 1888, pp. 1-6; 28 October 1889, p. 10.
National Library of Ireland. Group in motor cars, Bunmahon Co.,
Waterford. Retrieved from https://www.flickr.com/photos/nlireland/5774924883
on 2018-9-1.
National Archives Repository (TAB), Source MHG, Vol. 0, Ref. 72133: death notice, Herbert Tristman Marks.
National Automated Archival Information Retrieval System (NAAIRS). http://www.national.archives.gov.za/naairs.htm Documents relating to Marks, Herbert Tristman / Marks, Herbert T. / Marks, H.T.
Plug, C. Early scientific and professional societies in the Transvaal: Barberton 1887-1889. South African Journal of Cultural History, 1990, Vol. 4(3), pp. 190-199.