“Analysis of the Level of Upper Service Skills in Volleyball Games of Junior High School Extracurricular Students”. Jurnal Pendidikan Kepelatihan Olahraga: PEJUANG, vol. 2, no. 1, Feb. 2026, pp. 86-92, https://journalpejuang.web.id/index.php/jurnalpkopejuang/article/view/81.