1.
Heydari A, Soltani H, Mohammadi-Nezhad M. The effect of Psychological skills training (goal setting, positive selftalk and Imagery) on self-confidence of adolescent volleyball players. Pedagogics, psychology, medical-biological problems of physical training and sports. 2018;22(4):189-94. https://doi.org/10.15561/18189172.2018.0404