| Author | Title | Journal/publisher | Literature ref. no. |
| Fischer, E. (1999) | Scrophulariaceae | Flore d'Afrique Centrale (Congo-Kinshasa, Rwanda & Burundi) Jardin Botanique National de Belgique, Bruxelles | 1676 |
Note that the process of capturing references from species to the literature and the reverse may be incomplete.