Ron, S. R., E. Toral, M. Rivera, and A. Terán-Valdez. “A New Species of Engystomops (Anura: Leiuperidae) from Southwestern Ecuador”. Zootaxa, vol. 2606, no. 1, Sept. 2010, pp. 25–49, doi:10.11646/zootaxa.2606.1.2.