1. Appleman, Eric M. 2012. Obama-Biden Iowa Visits.
http://www.p2012.org/obama/obamaiavisits12.html
.
2. ———. 2017. Trump-Pence Iowa Visits.
http://www.p2016.org/trump/trumpiavisits16.html
.
3. Beaumont, Thomas. 2008. Iowans There for Obama at Race’s Start and Finish. Des Moines Register, November 5. ProQuest.
4. Cillizza, Chris, and Aaron Blake. 2011. Is Iowa a Swing State? The Fix (blog). Washington Post, August 16.
https://www.washingtonpost.com/blogs/the-fix/post/is-iowa-a-swing-state/2011/08/15/gIQAHG6tIJ_blog.html?utm_term=.1725fc95d2f0
.
5. Clopton, Andrew J., and C. Scott Peters. 2013. Justices Denied: A County-Level Analysis of the 2010 Iowa Supreme Court Retention Election. Justice System Journal 34 (3): 321–344.
https://doi.org/10.1080/0098261X.2013.10768043
.