Merxmueller, H. von & J. Cramer (1967). Prodromus: einer flora von Südwestafrika. 126: 12
Bibliography other :
Kolberg H. & M. van Slageren (2016). A synopsis of Aptosimum and Peliostomum (Scrophulariaceae) in Namibia, including the description of a new species, Aptosimum radiatum, and keys to all accepted species. Kew Bull. 71/16: 30 LT2