Węgrzyniak, A., W. Wokurka, I. Dudek, and P. Piech. “What Are the Newest Outcomes about Legg-Calve-Perthes Disease Etiology After 110 Years over Its Discovering ? – Literature Review”. Journal of Education, Health and Sport, vol. 11, no. 9, Sept. 2021, pp. 396-00, doi:10.12775/JEHS.2021.11.09.050.