Jasim, Osn. “Designing a Proposed Apparatus For Developing Concentration and Shifting Attention In Throwing Events Referees”. Journal of Physical Education 28, no. 2 (June 28, 2016): 445–458. Accessed June 26, 2026. https://www.jcope.uobaghdad.edu.iq/index.php/jcope/article/view/301.