List of sources:
Albany Museum. Annual Report, 1910, 1912, 1913.
Cruden, Frank. In: Biodiversity explorers, at http://www.biodiversityexplorer.org/people as on 2013-08-21.
Gunn, M. & Codd, L.E. Botanical exploration of southern Africa. Cape Town: Balkema, 1981.
National Automated Archival Information Retrieval System (NAAIRS), at http://www.national.archives.gov.za/naairs.htm Documents relating to Frank Cruden.
South African Association for the Advancement of Science. Report, 1915, 1916, papers by Cruden; 1918, list of members.
South African Journal of Natural History, 1926, Vol. 6(1), paper by Cruden.
University of the Cape of Good Hope. Calendar, 1905/6.