List of sources:
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Cape Mercury, 6 May 1886, p. 3, "The Naturalists Society".
Cape of Good Hope. Report of the Meteorological Commission, 1875-1908.
Cape of Good Hope. Report of the committee of the Public Museum, King William's Town, 1909.
Cape of Good Hope Government Gazette, 9 January 1885, pp. 41-45: List of licensed medical practitioners...
FamilySearch: Charles James Egan. https://www.familysearch.org/ark:/61903/3:1:3Q9M-CSQX-CSKC?view=index&personArk=/ark:/61903/1:1:QGVW-H8KS&action=view and https://www.familysearch.org/ark:/61903/3:1:33S7-95DP-JWJ?view=index&personArk=/ark:/61903/1:1:WXB2-1DZM&action=view
General directory and guide book to the Cape of Good Hope and its denpendencies, 1886, pp. 311-312.
Google scholar. http://scholar.google.co.za Publications by C.J. Egan.
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Laidler, P.W. & Gelfand, M. South Africa - its medical history, 1652-1898. Cape Town: Struik, 1971.
Men of the times: Old colonists of the Cape Colony and Orange River Colony. Johannesburg: Transvaal Publishing Company, 1906.
National Automated Archival Information Retrieval System (NAAIRS). http://www.national.archives.gov.za/naairs.htm Documents relating to Charles Egan / C.J. Egan.
Obituary: Charles James Egan, MRCS (Eng), LRCP (I). South African Medical Record, 1909, Vol. 7, pp. 94-95.
Randles, B.M. A history of the Kaffrarian Museum (pp. 1, 21). King William's Town: Kaffrarian Museum, 1984.
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South African who's who, 1908.