Jara, D., M.- Ángel Gómez, E. Ortega, and P. Sainz de Baranda. “DESIGN, VALIDATION, AND RELIABILITY OF AN OBSERVATIONAL INSTRUMENT FOR THE DEFENSIVE AND OFFENSIVE TECHNICAL-TACTICAL ACTIONS OF THE GOALKEEPER”. Kinesiology, vol. 52, no. 2, Dec. 2020, pp. 250-7, https://hrcak.srce.hr/ojs/index.php/kinesiology/article/view/6274.