Template:Maas et al., 2007
- Maas, P.J., Westra, L.Y. & Vermeer, M. 2007. Revision of the neotropical genera Bocageopsis, Onychopetalum, and Unonopsis (Annonaceae). Blumea-Biodiversity, Evolution and Biogeography of Plants 52(3): 413–554. Full text PDF