TSEBE, K. .; VAN NIEKERK, R. . Effect of a 7-week Mindfulness-Acceptance-Commitment intervention programme on mental toughness: An experimental study of male league softball players. African Journal for Physical Activity and Health Sciences, [S. l.], v. 27, n. 2, p. 192–201, 2021. DOI: 10.37597/ajphes.2021.27.2.5. Disponível em: https://www.ajol.info/index.php/ajpherd/article/view/212556. Acesso em: 12 nov. 2026.