E. C. H.  van Heusden, ?Flowers of Annonaceae: morphology, classification, and evolution?, Blumea SupplementBlumea Supplement, vol. 7, pp. 1-218, 1992.

E. C. H.  van Heusden, ?Flowers of Annonaceae: morphology, classification, and evolution?, Blumea Supplement, vol. 7, pp. 1-218, 1992.