«Cedar Rapids Gazette». Newspaperarchive.com. 5 de novembro de 2008. p. 1. Consultado em 20 de janeiro de 2016
worldcat.org
Redlawsk, David; Tolbert, Caroline J.; Donovan, Todd (2011). Why Iowa? : how caucuses and sequential elections improve the presidential nominating process. Chicago: University of Chicago Press. ISBN9780226706955. OCLC606053997
Larimer, Christopher W. (Christopher Wesley). Gubernatorial stability in Iowa : a stranglehold on power. [S.l.: s.n.] ISBN978-1-137-52814-8. OCLC934936718