ZUNITA, Indah; SRIWAHYUNIATI, Christina Fajar; TOMOLIYUS; SUKAMTI, Endang Rini. Relationship Between Self-Confidence and Concentration with the Smashing Ability of 12-17 Year Volleyball Athletes at the Pervas Club. Indonesian Journal of Sport Management, [S. l.], v. 5, n. 4, 2025. DOI: 10.31949/ijsm.v5i4.16184. Disponível em: https://www.ejournal.unma.ac.id/index.php/ijsm/article/view/16184. Acesso em: 13 jun. 2026.