KANGKONNOK, K.; LAUMKA, R. The Results of Problem-based Learning Experiences Management Towards the Mental Toughness of Early Childhood. Journal of Roi Et Rajabhat University, [S. l.], v. 19, n. 3, p. 43–58, 2025. Disponível em: https://so03.tci-thaijo.org/index.php/reru/article/view/291237. Acesso em: 16 sep. 2026.