Arslanoğlu, E., M. Tekin, C. Arslanoğlu, and İlker Özmutlu. “Investigation of Anxiety Levels and Basic Psychological Needs of Volleyball Referee Accoarding to Different Variables”. Journal of Human Sciences, vol. 7, no. 2, Nov. 2010, pp. 985-9, https://www.j-humansciences.com/ojs/index.php/IJHS/article/view/1215.