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Cape of Good Hope. Report of the Trustees of the South African Museum, 1898.
Cape Society of Civil Engineers. Minutes of Proceedings, 1902-1907, Vol. 1-5.
National Automated Archival Information Retrieval System (NAAIRS). http://national.archives.gov.za/naairs.htm Documents relating to Westhofen, Wilhelm / Westhofen, W.
National Union Catalogue, pre-1956 imprints. London: Mansell, 1968-1980.
Radnorshire Fine Arts Ltd. Westhofen, Wilhelm/William (1842-1925). Retrieved on 5 May 2021 from https://www.radnorshire-fine-arts.co.uk/brand/westhofen-wilhelm-william-1842-1925/
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South African Society of Civil Engineers. Minutes of Proceedings, 1913, Vol. 11, Members.