“THE EFFECT OF DRILL VARIATIONS TRAINING ON THE OVERHAND SERVE DEFENSE ABILITY IN VOLLEYBALL AT SMA HANG TUAH 1 SURABAYA”. Journal Sports Exercise Science International (SESI) 1, no. 1 (December 1, 2025): 60–63. Accessed February 22, 2026. https://sesi.karirpublisher.org/index.php/sesi/article/view/19.