List of sources:
Agricultural Journal of the Cape of Good Hope, 1910, Vol. 36 and 37, articles by N.S. Pillans.
Bolus, H. Icones Orchidearum Austro-Africanum Extra-Tropicum; or, figures with descriptions of extra-tropical South African orchids (Vol. 2, Preface). London: W. Wesley, 1911.
Bullock. A.A. Bibliography of South African Botany (up to 1951). Pretoria: Department of Agricultural Technical Services, 1978.
Cape of Good Hope. Report of the committee of the Albany Museum, 1908.
Dictionary of South African biography, Vol. 4, 1981.
Gunn, M. & Codd, L.E. Botanical exploration of southern Africa. Cape Town: Balkema, 1981.
National Automated Archival Information Retrieval System (NAAIRS). http://national.archives.gov.za/naairs.htm Documents relating to Pillans, N.S.
National Union Catalogue, pre-1956 imprints. London: Mansell, 1968-1980.
Oliver, E.G.H. [Obituary]: N.S. Pillans. Journal of the Botanical Society of South Africa, 1965, Vol. 51, pp. 42-43.
Phillips, E.P. A brief historical sketch of the development of botanical science in South Africa and the contribution of South Africa to botany. South African Journal of Science, 1930, Vol. 27, pp. 39-80.
Phillips, E.P. Memories of South African botanists. South African Journal of Science, 1965, Vol. 61, pp. 291-296.
Reynolds, G.W. The aloes of South Africa. Johannesburg: Aloes of South Africa Book Fund, 1950.
Royal Society of South Africa. Transactions, 1910, Vol. 1, list of members; 1928, Vol. 16, paper by N.S. Pillans.
Thiselton-Dyer, W.T. (ed.) Flora Capensis, preface to Vol. 4.1. London: L. Reeve, 1909.
Union of South Africa. Report of the South African Museum for the years 1910, 1911, 1912. Cape Town, 1913.
White, A. & Sloane, B.L. The Stapeliae (2nd ed., Vol. 1, pp. 128-130). Pasadena, 1937.