Pérez-Villalba, M., J. García-Fernández, R. Gómez-Chacón, and N. Fernández-Martínez. “Group Exercise Training in Sport Centers and Its Value As a Retention Element”. SPORT TK-EuroAmerican Journal of Sport Sciences 7, no. 2 (September 24, 2018): 17–26. Accessed October 19, 2026. https://revistas.um.es/sportk/article/view/343061.