Fischer, E., D. Killmann, and U. Meve. “Neoschumannia gishwatiensis (Apocynaceae, Asclepiadoideae-Ceropegieae) from Gishwati Forest, Rwanda—a Third and New Species from a Disjunct African Genus”. Phytotaxa, vol. 77, no. 2, Jan. 2013, pp. 19–26, doi:10.11646/phytotaxa.77.2.1.