Mahmuddin, M., D. Sihombing, R. S. ., Yunis Bangun, S. ., & Josua Hamonangan, D. . (2024). The effect of exercise variation methods on leg muscle strength and its contribution to improving volleyball smash results. Jurnal SPORTIF : Jurnal Penelitian Pembelajaran, 10(1), 126–138. https://doi.org/10.29407/js_unpgri.v10i1.22242