List of sources:
British Association for the Advancement of Science. Report of the seventy-fifth meeting... South Africa, 1905, list of members.
Cape of Good Hope. Report of the South African College, 1898, 1899.
Dictionary of South African biography, Vol. 4, 1981.
FamilySearch: Lawrence Crawford. https://www.familysearch.org/ark:/61903/1:1:6K1B-8YVF
Google scholar. http://scholar.google.co.za Publications by L. Crawford.
Journal of the Astronomical Society of South Africa, 1933, Vol. 3(3), paper by Crawford; 1938, Vol. 4(3), pp. 134-137: List of members.
Obituary: Lawrence Crawford. Transactions of the Royal Society of South Africa, 1955, Vol. 34, pp. xiv-xv.
Phillips, H. The University of Cape Town, 1918-1948: The formative years. University of Cape Town, 1993.
Ritchie, W. The history of the South African College, 1829-1918. Cape Town: T. Maskew Miller, 1918.
Royal Society of London. Catalogue of scientific papers [1800-1900]. London: Royal Society, 1867-1925.
Royal Society of South Africa. Transactions, 1908-1910, Vol. 1, and 1917, Vol. 6: Lists of Fellows and members; 1925, Vol. 12, Minutes of Proceedings; 1934, Vol. 22, paper by Crawford.
South African Association for the Advancement of Science. Report, 1903, 1904, 1907, 1908, 1910, 1913, 1916, 1918.
South African Journal of Science, 1928, Vol. 15, paper by Crawford.
South African Philosophical Society. Transactions, 1900-1907, Vol. 11, 16, 17: Lists of members.
Transvaal Agricultural Journal, 1906, Vol. 4, pp. 809-810: South African School of Forestry.
University of the Cape of Good Hope. Calendar, 1906/7-1908/9, 1917/8.
University of the Witwatersrand. Honorary Graduates. http://www.wits.ac.za/alumni/alumnirecognition/3600/honorary_degrees.html