B.  Sonké, Taedoumg, H., and Robbrecht, E., ?A reconsideration of the Lower Guinean species of Sericanthe (Rubiaceae, Coffeeae), with four new species from Cameroon and Gabon?, Botanical Journal of the Linnean Society, vol. 169, pp. 530-554, 2012.

V.  Droissart, Hardy, O., Sonké, B., Dahdouh-Guebas, F., and Stevart, T., ?Subsampling Herbarium Collections to Assess Geographic Diversity Gradients: A Case-Study with endemic Orchidaceae and Rubiaceae in Cameroon?, Biotropica, vol. 44, pp. 44-52, 2012.