H.P.Linder (Schltr.) 1981 - Linder HP (1981) Taxonomic Studies in the Disinae (Orchidaceae). IV. A Revision of Disa Berg. sect. Micranthae Lindl. Bulletin Du Jardin Botanique National De Belgique 51: 255-346. doi: 10.2307/3668067.
There is no corrections for Disa welwitschii subsp. occultans yet.