List of sources:
Appelgryn, M.S. Johannesburg: Origins and early management, 1886-1899. Pretoria: University of South Africa, 1984.
Cape of Good Hope. Report of the Surveyor-General, 1880, list of admitted land surveyors.
Dictionary of South African biography, Vol. 4, 1981.
Hurly, R.F. Presidential address: Astronomers and surveyors. MNASSA, 1979, Vol. 38(7-10), pp. 59-64.
Hurly, R.F. Josias Eduard de Villiers, surveyor and astronomer. South African Survey Journal, 1983, Vol. 19(2), pp. 24-28.
National Automated Archival Information Retrieval System (NAAIRS). http://www.national.archives.gov.za/naairs.htm Documents relating to De Villiers, Josias Eduard.
Shorten, J.R. The Johannesburg saga. Johannesburg: J.R. Shorten, 1970.
Transvaal almanac and directory, 1877, p. 69; 1881, p. 179: position of Bloemfontein.
Warner, B. & Hurly, R.F. J.E. de Villiers's observatory at Sea Point. MNASSA, 1976, Vol. 35(5-6), pp. 57-62.