Gordon, Matthew J. (2004). "The West and Midwest: phonology." Kortmann, Bernd, Kate Burridge, Rajend Mesthrie, Edgar W. Schneider and Clive Upton (eds). A Handbook of Varieties of English. Volume 1: Phonology, Volume 2: Morphology and Syntax. Berlin / New York: Mouton de Gruyter. p. 347.