1. Jacoby, E., Bull, F., & Neiman, A. (2003). Rapid changes in lifestyle make increased physical activity a priority for the Americas. Revista Panamericana de Salud Publica, 14, 226–228.
2. Pan American Health Organization. (2011). Regional strategy and plan of action on an integrated approach to the prevention and control of chronic diseases. Retrieved January 5, from http://www.paho.org/english/ad/dpc/nc/reg-strat-cncds.pdf .
3. Owen, N., Humpel, N., Leslie, E., Bauman, A., & Sallis, J. F. (2004). Understanding environmental influences on walking: review and research agenda. American Journal of Preventive Medicine, 27, 67–76.
4. Parra, D., Gomez, L., Pratt, M., Sarmiento, O. L., Mosquera, J., & Triche, E. (2007). Policy and built environment changes in Bogotá and their importance in health promotion. Indoor and Built Environment, 16, 344–348.
5. US Department of Health and Human Services. (1996). Physical activity and health: a report of the Surgeon General. US Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion.