Dr. Sabah Mohammed Yaseen. “THE EFFECT OF SELF-CONFIDENCE EXERCISES TO RAISE THE PERFORMANCE LEVEL OF THE SMASH SERVE AND SMASH SPIKING SKILLS IN VOLLEYBALL FOR JUNIORS”. ResearchJet Journal of Analysis and Inventions, vol. 3, no. 05, May 2022, pp. 27-39, doi:10.17605/OSF.IO/CB4FU.