WOJDAT, Marta, KANUPRIYA, Rawat, JANOWSKA, Patrycja, WOLSKA, Beata, STĘPNIAK, Robert and ADAM, Marek. Comparative analysis of optimism and life satisfaction in Brazilian male and female Ju-Jitsu society. Journal of Education, Health and Sport. Online. 13 December 2017. Vol. 7, no. 12, pp. 139-154. [Accessed 16 July 2024].