Marshall, S. W., Covassin, T., Dick, R., Nassar, L. G., & Agel, J. (2007). Descriptive epidemiology of collegiate women's gymnastics injuries: National Collegiate Athletic Association Injury Surveillance System, 1988–1989 through 2003–2004. Journal of athletic training, 42(2), S. 234-240. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1941288/

Marshall, Stephen W., Tracey Covassin, Randall Dick, Lawrence G. Nassar, and Julie Agel. "Descriptive Epidemiology of Collegiate Women's Gymnastics Injuries: National Collegiate Athletic Association Injury Surveillance System, 1988–1989 Through 2003–2004." Journal of Athletic Training 42, no. 2 (2007): S. 234-240.

Marshall, Stephen W., et al. "Descriptive Epidemiology of Collegiate Women's Gymnastics Injuries: National Collegiate Athletic Association Injury Surveillance System, 1988–1989 Through 2003–2004." Journal of Athletic Training 42.2 (2007): S. 234-240.