Mrozkowiak, M., A. I. Bereznyakova, V. F. Cheremisina, and W. Zukow. “O narzędziach I Wynikach Badań = About the Tools and the Results of the Research”. Journal of Education, Health and Sport, vol. 5, no. 11, Nov. 2015, pp. 245-60, https://apcz.umk.pl/JEHS/article/view/3096.