List of sources:
Annals of the Natal Museum, 1913-1937, Vol. 2-8, papers by Hewitt.
Annals of the Transvaal Museum, 1909-1935, Vol. 2-16, papers by Hewitt.
Ashton, E.H. Southern African Ornithological Society. Bokmakierie, 1980, Vol. 32, pp. 26-76.
Binneman, J. A history of archaeology in Eastern Cape. The Phoenix, May 1990, Vol. 3(1), pp. 12-15.
Cape of Good Hope. Report of the Committee of the Albany Museum, 1909.
Cape of Good Hope. Report of the Committee of the Public Museum, King William's Town, 1909.
Cape of Good Hope. Report of the Trustees of the South African Museum, 1909.
Dictionary of South African biography, Vol. 4, 1981.
FamilySearch: John Hewitt. https://www.familysearch.org/ark:/61903/3:1:3Q9M-C91P-K9TG-J?view=index&personArk=/ark:/61903/1:1:6CYC-Z8M4&action=view&cc=3732506
Goodwin, A.J.H. A commentary upon South African prehistory up to the introduction of the new terminology. Bantu Studies, 1935, Vol. 9, pp. 291-333; bibliography pp. 387-413.
National Automated Archival Information Retrieval System (NAAIRS). http://www.national.archives.gov.za/naairs.htm Documents relating to Hewitt, John.
[Obituary]: Dr John Hewitt. South African Archaeological Bulletin, 1961, Vol. 16, p. 121.
[Obituary: Dr John Hewitt. The Ostrich, 1961, Vol. 32(3), p. 146.
Obituary: John Hewitt. South African Journal of Science, 1961, Vol. 57, p. 312.
Records of the Albany Museum, 1911-1935, Vol. 2-4: Papers by Hewitt.
Royal Society of South Africa. Transactions, 1913-1938, Vol. 3-26: Papers by Hewitt, lists of Fellows and members.
Senior Captain Scott Memorial Medal. Journal of the South African Biological Society, 1968, Vol. 9, pp. 39-40.
South African Association for the Advancement of Science. Report, 1909-1919: Papers by Hewitt, office bearers and lists of members.
South African Journal of Natural History, 1918, Vol. 1(1), pp. 8-15: Roll of Foundation Members [of the SA Biological Society]; 1920, Vol. 2(2), Roll of members.
South African Journal of Science, 1922-1936, Vol. 19-33, papers by Hewitt.
Southern African Museums Association Bulletin (SAMAB), 1939-1942, Vol. 1-2, papers by Hewitt.
The Transvaal Biological Society. South African Journal of Natural History, 1918, Vol. 1(1), pp. 21-32.
Twenty-sixth award of the South Africa Medal and grant. South African Journal of Science, 1936, Vol. 33, pp. xxxvii-xliii.