R. W. J.  Keay, ?Revision of the "Flora of West Tropical Africa", I - Annonaceae?, Kew BulletinKew Bulletin, vol. 7, pp. 149-157, 1952.

R. W. J.  Keay, Trees of Nigeria. Oxford: Clarendon Press, 1989.

R. W. J.  Keay, ?Revision of the "Flora of West Tropical Africa", I - Annonaceae?, Kew Bulletin, vol. 7, pp. 149-157, 1952.