Khalid Shakir, et al. “The Most Important Emotional Determinants and Their Relationship to the Spirit of Challenge Among Advanced Handball Players in Babil Governorate Clubs”. Modern Sport, vol. 18, no. 3, Sept. 2019, pp. 261-70, https://jcopew.uobaghdad.edu.iq/index.php/sport/article/view/1484.