B.  Sonké, Nguembou, C., Cheek, M., and Davis, A., ?A new species of Chassalia (Rubiaceae, Rubioideae) from southern Cameroon: C. bipindensis?,  Kew Bull., vol. 61, no. 4, p. 589, 2006.

B.  Sonké, Nguembou, K. C., and Davis, A. P., ?A new dwarf Coffea (Rubiaceae) from southern Cameroon?, Botanical Journal of the Linnean Society, vol. 151, pp. 425-430, 2006.

B.  Sonké, Nguembou, K. C., and Neuba, D., ?Les Rubiaceae endémiques du Cameroun et leur statut de conservation?, in Taxonomy and ecology of African plants, their conservation and uses. Proceedings du XVIIème Congrès de l'Aetfat, S. A.  Ghazanfar and Beentje, H. J., Eds. London: Royal Botanic Garden Kew, 2006, pp. 97-109.

D. F. R.  Neuba, Lejoly, J., and Sonké, B., ?A new Leptactina (Rubiaceae, Pavetteae) from Central African Republic: Leptactina deblockiae?, Adansonia, vol. 28, pp. 373-378, 2006.

C.  Nguembou, Esono, P., Onana, J. Michel, and Sonké, B., ?A new heterophyllous Bertiera (Rubiaceae) from Cameroon and Gabon?, Systematics and Geography of Plants, vol. 76, pp. 211-216, 2006.

E.  Robbrecht and Manen, J. F., ?The major evolutionary lineages of the coffee family (Rubiaceae, angiosperms). Combined analysis (nDNA and cpDNA) to infer the position of Coptosapelta and Luculia, and supertree construction based on rbcL, rps16,<i> trnL-trnF<?, Systematics and Geography of Plants, vol. 76, pp. 85-145, 2006.