Bruyns, P.V. 1999. The systematic position of Quaqua (Apocynaceae, Asclepiadpoideae) with a critical revision of the species. Botanische Jahrbücher für Systematik 121(3):311-402.
Bruyns, P.V. 2005. Stapeliads of southern Africa and Madagascar. (Vol. 1, pp. 1-330). Umdaus Press, Pretoria.
Hilton-Taylor, C. 1996. Red data list of southern African plants. Strelitzia 4. South African National Botanical Institute, Pretoria.
Raimondo, D., von Staden, L., Foden, W., Victor, J.E., Helme, N.A., Turner, R.C., Kamundi, D.A. and Manyama, P.A. 2009. Red List of South African Plants. Strelitzia 25. South African National Biodiversity Institute, Pretoria.
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