[1]
M. M. Margarita Villamizar, J. F. Acosta Muñoz, J. G. Cuadros Molano, and J. C. Montoya, “Motivational factors of professional footballers, as sportsmen and internal customers in Boyaca, Colombia”, Int. j. psychol. res., vol. 2, no. 2, pp. 148–157, Dec. 2009.