Analysis of The Mental Level of Competition in North Sumatra Tennis Athletes at Pon XXI Aceh – North Sumatra 2024. Journal Coaching Education Sports, [S. l.], v. 6, n. 2, p. 57–66, 2024. DOI: 10.31599/ayfdb273. Disponível em: https://ejurnal.ubharajaya.ac.id/index.php/JCESPORTS/article/view/3837.. Acesso em: 8 dec. 2025.