PROSKURA, Patrycja; WITKOWSKI, Kazimierz. The law on sport in the light of the opinion of the fitness instructors and personal trainers. Journal of Education, Health and Sport, [S. l.], v. 7, n. 6, p. 789–800, 2017. Disponível em: https://apcz.umk.pl/JEHS/article/view/4982. Acesso em: 26 dec. 2024.