Katz, Josh: Speaking American: How Y’all, Youse, and You Guys Talk: A Visual Guide. Houghton Mifflin Harcourt, 25.10.2016. ISBN 0544703391Teoksen verkkoversio.
Hickey, Walter: 22 Maps That Show How Americans Speak English Totally Differently from One Another. Business Insider, 5 June 2013. Artikkelin verkkoversio. (englanti)