Merchan Osorio, R. D., J. Flórez Flórez, and W. F. Caro Cely. “Methods of Soccer Teaching in Sports Training Schools in Tunja, Boyacá”. Revista Docencia Universitaria, vol. 18, no. 2, Dec. 2017, pp. 41-52, https://revistas.uis.edu.co/index.php/revistadocencia/article/view/9147.