Martín Butragueño, P. 2002. Ralph Penny, Variation and change in Spanish. Cambridge University Press, Cambridge, 2000; xiv + 284 pp. Nueva Revista de Filología Hispánica (NRFH). 50, 1 (ene. 2002), 222–226. DOI:https://doi.org/10.24201/nrfh.v50i1.2538.