“The Effect of Arm Power Training On Upper Service Ability In Volleyball Games of Extracurricular Students of Palu Salvation Army Christian Junior High School” (2025) COMPETITOR: Jurnal Pendidikan Kepelatihan Olahraga, 17(2), pp. 1792–1800. Available at: https://competitor.idjournal.eu/index.php/competitor/article/view/260 (Accessed: 19 March 2026).