Endangered Languages Catalogue Project. Compiled by research teams at University of Hawai'i Mānoa and Institute for Language Information and Technology (LINGUIST List) at Eastern Michigan University . (2012) ·

Ethnologue: Languages of the World, 16th Edition (2009) . (2009) · edited by M. Paul Lewis · SIL International http://www.ethnologue.com/

World Oral Literature Project . http://www.oralliterature.org

Endangered Languages in Mexico ( pp. 93-134 ) . Beatriz Garza Cuarón and Yolanda Lastra (1991) · In Endangered Languages edited by R. H. Robins and E. M. Uhlenbeck · New York: Berg

La población hablante de lengua indígena en México . (1993) ·

Meso-America ( pp. 197-209 ) . William Adelaar and J. Diego Quesada (2007) · In Encyclopedia of the World's Endangered Languages edited by Christopher Moseley · London and New York: Routledge

Atlas of the World’s Languages in Danger . Christopher Moseley (ed.) (2010) · UNESCO Publishing http://www.unesco.org/culture/en/endangeredlanguages/atlas