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

Ethnologue: Languages of the World, 17th Edition (2013) . (2013) · edited by Paul M. Lewis; Gary F. Simons; and Charles D. Fennig · Dallas, Texas: SIL International http://www.ethnologue.com Ethnologue: Languages of the World, 17th Edition (2013)

Glottolog . http://www.glottolog.org/glottolog/

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) ·