Phonological Atlas of North America. Prepared by William Labov,Sharon Ash,Charles Boberg,David Bowie,Atissa Banuazizi,Carol Orr,Anita Henderson,Joyce Albergottie,and Tom Maciejewski. http://www.ling.upenn.edu/phono_atlas/ home.html

Carver, Craig. 1987. American Regional English Ann Arbor : University of Michigan Press.

Davis, Lawrence M. , and Charles L. Houck . 1992. Is There a Midland Dialect Area?—Again American Speech 67:61-70.

Frazer, Timothy. 1987. Midland Illinois Dialect Patterns. PADS 73 Tuscaloosa: University of Alabama Press .

—. 1993. "Heartland" English: Variation and Transition in the American Middle West Tuscaloosa: University of Alabama Press.

—. 1994. On Transition Areas and the "Midland" Dialect: A Reply to Davis and Houck American Speech 69:430-35.

Johnson, Ellen. 1994. Yet Again: The Midland Dialect American Speech 69:419-29.

. 1996. Lexical Change and Variation in the Southeastern United States 1930-1990 Tuscaloosa: University of Alabama Press.

Kretzschmar, William A. Jr., Virginia G. McDavid, Theodore K. Lerud, and Ellen Johnson, eds. 1993. Handbook of the Linguistic Atlas of the Middle and South Atlantic States. Chicago: University of Chicago Press.

Labov, William. 1991. The Three Dialects of English. In New Ways of Analyzing Sound Change, edited by P. Eckert, 1-44. Orlando, FL: Academic Press.