List of sources:
Journal of the Chemical, Metallurgical and Mining Society of South Africa, 1905, Vol. 5, Members.
National Archives Repository (TAB), Source MHG, Vol. 0, Ref. 86327: death notice, Robert Pender Whitelaw.
National Automated Archival Information Retrieval System (NAAIRS). http://national.archives.gov.za/naairs.htm Documents relating to Whitelaw, Robert Pender / Whitelaw, Robert P. / Whitelaw, R.P.
Orr, J. Presidential address. Associated Scientific and Technical Societies of South Africa, Annual Proceedings, 1938, pp. 15-86.
Robert Pender Whitelaw. My Heritage. Retrieved on 20 May 2021 from https://www.myheritage.com/names/robert_whitelaw
Who was who, Vol. 3, 2nd ed. London: Adam & Black, 1967.