List of sources:
Ashton, E.H. Southern African Ornithological Society. Bokmakierie, 1980, Vol. 32, pp. 26-76.
Cape of Good Hope. Report on the Albany Museum, 1892.
Cape of Good Hope. Report on the Port Elizabeth Museum, 1894, 1895.
Cape of Good Hope. Report of the trustees of the South African Museum, 1898.
Eastern Province Naturalists' Society. Ninth Annual Report, 1890, list of members. Port Elizabeth: J. Kemsley, 1891.
Eastern Province Naturalists' Society. Minute Book 2, 1885-1892, p. 107. (Africana collection, Port Elizabeth Public Library).
E.P. Magazine, January 1893, Vol. 1(2), p. 32, Natural History Section.
FamilySearch: Robert Henry Ivy. https://www.familysearch.org/ark:/61903/3:1:9Q97-Y3QD-211?view=index&personArk=/ark:/61903/1:1:Q2QM-33F4&action=view&cc=1779109 AND https://www.familysearch.org/ark:/61903/1:1:6ZHB-H9QQ
Google scholar. http://scholar.google.co.za Publications by Robert Henry Ivy.
Journal of the South African Ornithologists' Union, 1905-1907, Vol. 1-3; 1909, Vol. 5(3), list of members.
South African bibliography to the year 1925. London: Mansell, 1979.
South African who's who, 1919/20, John Robson Ivy.
Transvaal Museum. Annual Report, 1905-6. In Transvaal Administration Reports, 1905-6, pp. G1-G20. (Transvaal Archives Depot, Vol. TKP196).