F. Chacón-Borrego, C. Castañeda-Vázquez, J. Del Pozo-Cruz, and J. A. Corral-Pernía, “Social use of internet in adolescents: Relationship with cyberbullying and levels of physical activity”, J. Hum. Sport Exerc., vol. 13, no. 2proc, pp. S209-S220, Jul. 2018.