Santopietro, F., S. Fattore, F. Di Domenico, and I. Sannicandro. “Tennis and Learning through the Fit Junior Program: Observations and Results for the Didactics Aim”. Journal of Human Sport and Exercise, vol. 15, no. 3proc, Sept. 2020, pp. S619-S627, https://www.jhse.ua.es/article/view/2020-v15-n3-proc-tennis-learning-fit-junior-program-didactics.