1. 1. CARRON, A. V., L. R. BRAWLEY & W. N. WIDMEYER, 1998. The measurement of cohesiveness in sport groups. In J. L. DUDA (Ed.) Advances in sport and exercise psychology measurement Morgantown. WV: Fitness Information Technology, p. 213-226.
2. 2. ABDEL HAFEEZ EKHLAS & MUSTAFA BAHI, 2001. The Mathematical Meeting, The Book Center for Publishing, Cairo, p. 89.
3. 3. MUSTAFA MOHAMMED, 1998. Sociology of Sports. Al-Shuaa Press, Cairo, p.55.
4. 4. MOHAMED HASSAN ALLAWI, 1998. The Psychology of Sports Groups, The Book Center for Publishing, Cairo, p. 407.
5. 5. AL ARABI CHAMGHOUN, 2012. Psychology of sports competitions I 1, Press Faculty of Physical Education in Pyramid, Helwan University.