| Author | Title | Journal/publisher | Literature ref. no. |
| Leeuwenberg, A.J.M. & Bamps, P. (1979) | Loganiaceae | Flore d'Afrique Centrale (Zaire - Rwanda - Burundi) Jardin Botanique National de Belgique | 1504 |
Note that the process of capturing references from species to the literature and the reverse may be incomplete.