Kann, L., Kinchen, S., Shanklin, S. L., Flint, K.H., Hawkins, J., Harris, W. A., … Zaza, S. (2014). Youth Risk Behavior Surveillance — United States, 2013. Morbidity and Mortality Weekly Report [MMWR], 63(4), 1-168. Retrieved from http://www.cdc.gov/mmwr/pdf/ss/ss6304.pdf