1. Agans, J. P., & Geldhof, G. J. (2012). Trajectories of participation in athletics and positive youth development: The influence of sport type. Applied Developmental Science, 16(3), 151–165.
2. Agans, J. P., Säfvenbom, R., Davis, J. L., Bowers, E. P., & Lerner, R. M. (2013). Positive movement experiences: Approaching the study of athletic participation, exercise, and leisure activity through relational developmental systems theory and the concept of embodiment. In J. Benson & R. M. Lerner (Eds.), Advances in child development and behavior (Vol. 45, pp. 261–286). London, England: Elsevier.
3. Anderson-Butcher, D., Newsome, W. S., & Ferrari, T. (2003). Participation in boys and girls clubs and relationships to youth outcomes. Journal of Community Psychology, 1(31), 39–55.
4. Asparouhov, T., & Muthén, B. (May 22, 2012). Using Mplus TECH11 and TECH14 to test the number of latent classes. Mplus Web Notes: No. 14. Retrieved from http://statmodel.com/examples/webnotes/webnote14.pdf .
5. Asparouhov, T., & Muthén, B. (2013). Auxiliary variables in mixture modeling: 3-Step approaches using Mplus. Mplus Web Notes: No. 15. Retrieved from http://www.statmodel.com/examples/webnote.shtml .