F.  Weberling and Hoppe, J. R., ?Comparative morphology evaluation of inflorescence characters in Annonaceae?, in Reproductive morphology in Annonaceae, W.  Morawetz and Winkler, H., Eds. Vienna: Osterreichische Akademie der Wissenschaften, 1996, pp. 29-53.

P.  Leins and Erbar, C., ?Reproductive Morphology in Annonaceae?, in Early floral developmental studies in Annonaceae ? Biosystematics and Ecology Series, vol. 10, W.  Morawetz and Winkler, H., Eds. Wien: Akademie der Wissenschaften, 1996, pp. 1-27.