Ávalos Guillén, J. C., Gutiérrez Vargas, R., Araya Varas, G. A., Sánchez Ureña, B., Gutiérrez Vargas, J. C., & Rojas Valverde, D. (2017). Effects of Artificial Turf and Natural Grass on Physical and Technical Performance of Professional Soccer Players. Universidad Nacional, Costa Rica.

Ávalos Guillén, Juan Carlos, Randall Gutiérrez Vargas, Gerardo Alonso Araya Varas, Braulio Sánchez Ureña, Juan Carlos Gutiérrez Vargas, and Daniel Rojas Valverde. Effects of Artificial Turf and Natural Grass On Physical and Technical Performance of Professional Soccer Players. Universidad Nacional, Costa Rica, 2017.

Ávalos Guillén, Juan Carlos, et al. Effects of Artificial Turf and Natural Grass On Physical and Technical Performance of Professional Soccer Players. Universidad Nacional, Costa Rica, 2017.