(1)
Álvarez Bogantes, C.; Villalobos Víquez, G.; Rodríguez Méndez, D.; Herrera Monge, M. F.; Delgado Valverde, A. Physical Activity Levels at School: Use of the System for Observing Play and Leisure Activity in Youth (SOPLAY). Rev. Educación 2019, 44, 158-171.