1. National Council on Youth Sports. Report on trends and participation in organized youth sports. 2008. Available at: http://www.ncys.org/pdfs/2008/2008-ncys-market-research-report.pdf.
2. Youth risk behavior surveillance–United States, 2013;Kann;MMWR Surveill Summ,2014
3. “Hey, data data – swing!”;Kelley;ESPN The Magazine,2013
4. Epstein D. Hyperspecialization is ruining youth sports—and the kids who play them. 2014. Available at: http://www.propublica.org/article/hyperspecialization-is-ruining-youth-sportsand-the-kids-who-play-them. Accessed October 16, 2014.
5. The most expensive game in town. The rising cost of youth sports and the toll on today's families;Hyman,2012