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

The World Atlas of Language Structures . (2005) · edited by Bernard Comrie and David Gil and Martin Haspelmath and Matthew S. Dryer · Oxford University Press

Meso-America ( pp. 197-210 ) . Willem Adelaar (2007) · In Atlas of the World's Endangered Languages edited by C. Moseley · London & New York: Routledge

Sayula Popoluca morpho-syntax ( pp. 183-198 ) . Clark, Lawrence (1962) · International Journal of American Linguistics. 28

Sayula Popoluca texts, with grammatical outline ( pp. vii+216 ) . Clark, Lawrence E. (1961) · Linguistic Series · Vol. 6 · Summer Institute of Linguistics of the University of Oklahoma

Vocabulario Popoluca de Sayula: Popoluca-castellano, castellano-popoluca ( pp. 165 ) . Clark, Lawrence Lorenzo E. and Clark, Nancy Davis (1960) · Vocabularios Indigenas. Mariano Silva y Aceves ·

Sayula Popoluca morphosyntax ( pp. 183-198 ) . Clark, Lawrence (1962) · International Journal of American Linguistics. 28

Vocabulario Popoluca de Sayula . Clark, Lorenzo and de Clark, Nancy Davis (1974) · Instituto Lingüıstico de Verano