M.-O. Rödel, A. B. Onadeko, M. F. Barej, and L. Sandberger, “A new polymorphic Phrynobatrachus (Amphibia: Anura: Phrynobatrachidae) from western Nigeria”, Zootaxa, vol. 3328, no. 1, pp. 55–65, May 2012.