Cordes, R., Chapman, R., & Williams, R. N. (2016). Wildlife Habitat Education Program: Wildlife Identification Guide. Purdue University Cooperative Extension Service, (FNR-515-W), 102.
Sudkamp, S., & Chapman, R. (2015). Quail Habitat: Putting the Numbers in Perspective. Purdue University Cooperative Extension Service, FNR-514-W, 6. Retrieved from https://www.extension.purdue.edu/extmedia/FNR/FNR-514-W.pdf