Sadock, Jerrold M. 2003. "A Grammar of Kalaallisut (West Greenlandic Inuttut)." 162: München: Lincom.

Rudes, Blair A., Thomas J. Blumer and Alan J. May. 2004. "Catawba and Neighboring Groups." In Southeast, edited by Raymond D. Fogelson. 14: 301-318. Washinton, D. C.: Smithsonian Institution.

Rude, Noel E. Studies in Nez Perce Grammar and Discourse. PhD thesis, University of Oregon, 1985.

Rood, David S. and Allan R. Taylor. 1996. "Sketch of Lakhota, a Siouan Language." In Languages, edited by Ives Goddard. 17: 440-482. Washinton, D.C.: Smithsonian Institution.

Rood, David S. 1996. "Sketch of Wichita, a Caddoan Language." In Languages, edited by Ives Goddard. 17: 580-608. Washington, D.C.: Smithsonian Institution.

Rood, David S. 1976. "Wichita Grammar." New York: Garland.

Rogers, Daniel J. and III, George Sabo. 2004. "Caddo." In Southeast, edited by Raymond D. Fogelson. 14: 616-631. Washinton, D. C.: Smithsonian Institution.

Robinson, Lila Wistrand and James Armagost. 1990. "Comanche Dictionary and Grammar." 92: The Summer Institute of Linguistics and the University of Texas at Arlington.

Robins, Robert H. 1958. "The Yurok Language: Grammar, Texts and Lexicon." 15: Berkeley and Los Angeles: University of California Press.

Robinett, Florence M. 1955. "Hidatsa." In International Journal of American Linguistics, 21: 1-7, 160-177, 210-216.