B.  Verstraete, Lachenaud, O., Smets, E., Dessein, S., and Sonké, B., ?Taxonomy and phylogenetics of Cuviera (Rubiaceae?Vanguerieae) and reinstatement of Globulostylis with the description of three new species?, Botanical Journal of Linnean Society, vol. 173, pp. 407-441, 2013.