Cifuentes, E. ., and G. Salamanca. “Lexical Bifurcation in Protodoublets doctor/dostor, fuerte/juerte, buena/güena, último/úrtimo and humilde/humirde: Evidences from the Morphosyntactic Distribution and the Reaction of a Focus Group”. Onomázein, no. 38, Dec. 2017, pp. 188-12, doi:10.7764/onomazein.38.08.