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Idiomas mayas: Número de hablantes y extension territorial . Liliana Pellicer (2005) · Revista D. Prensa Libre http://douglasvasquez.blogspot.com/2011/03/idiomas-mayas-numero-de-hablantes-y.html and http://www.monografias.com/trabajos-pdf2/guatemala-lenguas-mayas-desaparecer/guatemala-lenguas-mayas-desaparecer.pdf