Callaghan, Catherine (1997). "Evidence for Yok-Utian". International Journal of American Linguistics. 63 (1): 18–64. JSTOR1265864.
Callaghan, Catherine (2001). "More Evidence for Yok-Utian: A Reanalysis of the Dixon and Kroeber Sets". International Journal of American Linguistics. 67 (3): 313–345. JSTOR1265989.
Callaghan, Catherine (2014). Proto-Utian Grammar and Dictionary: with notes on Yokuts. Trends in Linguistics Documentation. Vol. 31. Berlin, Boston: De Gruyter Mouton. doi:10.1515/9783110276770.
Goddard, Ives (1996). Goddard, Ives (ed.). "The Classification of the Native Languages of North America". Languages. Handbook of North American Indians. 17. Washington, DC: Smithsonian Institution: 290–324. ISBN0-16-048774-9.
Golla, Victor (2007). Jones, Terry L.; Klar, Kathryn A. (eds.). "Linguistic Prehistory". California Prehistory: Colonization, Culture, and Complexity. New York: Altamira Press: 71–82. ISBN978-0-7591-0872-1.