Abd K, Kadhim A. The Effect of a Training Program to Develop Speed Endurance and (YOYO) Test for Football Referees Level 2. jope [Internet]. 2016 Sep. 28 [cited 2026 Jul. 7];28(3):376-89. Available from: https://www.jcope.uobaghdad.edu.iq/index.php/jcope/article/view/1080