Manzano-Sánchez, D., and A. Valero-Valenzuela. “Differences Between Students According to Physical Activity and Their Motivation, Basic Psychological Needs and Responsibility”. Journal of Human Sport and Exercise, vol. 13, no. 2proc, July 2018, pp. S221-S230, doi:10.14198/jhse.2018.13.Proc2.06.