Agel, J., Evans, T. A., Dick, R., Putukian, M., & Marshall, S. W. (2007). Descriptive epidemiology of collegiate men's soccer injuries: National Collegiate Athletic Association Injury Surveillance System, 1988–1989 through 2002–2003. Journal of athletic training, 42(2), S. 270-277. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1941292/

Agel, Julie, Todd A. Evans, Randall Dick, Margot Putukian, and Stephen W. Marshall. "Descriptive Epidemiology of Collegiate Men's Soccer Injuries: National Collegiate Athletic Association Injury Surveillance System, 1988–1989 Through 2002–2003." Journal of Athletic Training 42, no. 2 (2007): S. 270-277.

Agel, Julie, et al. "Descriptive Epidemiology of Collegiate Men's Soccer Injuries: National Collegiate Athletic Association Injury Surveillance System, 1988–1989 Through 2002–2003." Journal of Athletic Training 42.2 (2007): S. 270-277.