Wojdat, Marta, Rawat Kanupriya, Patrycja Janowska, Beata Wolska, Robert Stępniak, and Marek Adam. “Comparative Analysis of Optimism and Life Satisfaction in Brazilian Male and Female Ju-Jitsu Society”. Journal of Education, Health and Sport 7, no. 12 (December 13, 2017): 139–154. Accessed July 16, 2024. https://apcz.umk.pl/JEHS/article/view/5073.