List of sources:
Dictionary of South African biography, Vol. 1, 1968: Henry Burton.
FamilySearch: Helen Marie Rousseau Kannemeyer Burton. https://www.familysearch.org/ark:/61903/1:1:68Y9-GD8H
Gunn, M. & Codd, L.E. Botanical exploration of southern Africa. Cape Town: Balkema, 1981.
JSTOR Global plants, at http://plants.jstor.org/person/bm000033830
National Automated Archival Information Retrieval System (NAAIRS), at http://www.national.archives.gov.za/naairs.htm Documents relating to Helen Marie Kannemeyer.
University of the Cape of Good Hope. Calendar, 1903/4.
Van Zyl, A.J. Twee dokters van Clanwilliam. Lantern, 1992, Vol. 41(2), pp. 9-14.
Women of South Africa. Cape Town: Le Quesne & Hooton-Smith, 1913.