List of sources:
Cape of Good Hope. Report of the Meteorological Commission, 1906, 1907, 1908.
Gill, D. A history and description of the Royal Observatory, Cape of Good Hope. London: HMSO, 1913.
Google scholar. http://scholar.google.co.za Publications by S.S. Hough.
Journal of the Astronomical Society of South Africa, 1923, Vol. 1(1), Officers and Council, 1922/3.
Long, A.W. The foundation and development of the Astronomical Society of South Africa. Journal of the Astronomical Society of South Africa, 1930, Vol. 2(4), pp. 153-180.
Memoirs: Sydney Samuel Hough, MA, FRS. Journal of the Astronomical Society of South Africa, 1923, Vol. 1(2), pp. 27-31.
Obituary: S.S. Hough. The Observatory, 1923, Vol. 44, pp. 269-272. Retrieved from http://adsbit.harvard.edu//full/1923Obs....46..269D/0000269.000.html
on 2017-12-4.
[Obituary]: Mr S.S. Hough. Transactions of the Royal Society of South Africa, 1926, Vol. 13, p. ii.
Royal Society of South Africa. Transactions, 1908-10, Vol. 1; 1917, Vol. 6: Lists of office bearers, fellows and members.
South African Association for the Advancement of Science. Report, 1903, 1905/6, 1908, 1910, 1918: Lists of office bearers and members.
South African bibliography to the year 1925. London: Mansell, 1979.
South African Philosophical Society. Transactions, 1900, Vol. 11; 1907, Vol. 17: Lists of members.
South African who's who, 1908, 1919/20.
Warner, B. Astronomers at the Royal Observatory, Cape of Good Hope. Cape Town: Balkema, 1979.