Buchner DM (2012). Physical activity. In L Goldman, A Shafer, eds., Cecil Medicine, 24th ed., pp. 56-58. Philadelphia: Saunders.
Wiles NJ, et al. (2007). Physical activity and common mental disorders: Results from the Caerphilly study. American Journal of Epidemiology, 165(8): 946-954.
Cipriani A, et al. (2011). Depression in adults (drug and other physical treatments), search date June 2009. BMJ Clinical Evidence. Available online: http://www.clinicalevidence.com.