The Optimism Expression for Middle School Age Students in Physical Education Classes. Baltic Journal of Sport and Health Sciences, [S. l.], v. 4, n. 99, 2015. DOI: 10.33607/bjshs.v4i99.100. Disponível em: https://journals.lsu.lt/baltic-journal-of-sport-health/article/view/100. Acesso em: 7 apr. 2025.