R. H. J.  Erkens, Chatrou, L. W., Koek-Noorrnan, J., Maas, J. W., and Maas, P. J. M., ?Classification of a large and widespread genus of Neotropical trees, Guatteria (Annonaceae) and its three satellite genera Guatteriella, Guatteriopsis and Heteropetalum?, TaxonTaxon, vol. 56, pp. 757-774, 2007.