Sadziak, A., W. Wiliński, and M. Wieczorek. “Ego-Resiliency the Female Students of the University School of Physical Education in Wroclaw - Pilot Study”. Journal of Education, Health and Sport, vol. 7, no. 2, Feb. 2017, pp. 207-21, https://apcz.umk.pl/JEHS/article/view/4262.