Stecko, M., A. Wawryków, K. Korabiusz, M. Fraszczyk, and A. Kordek. “Use of Botulinum Toxin in Children With Cerebral Palsy”. Journal of Education, Health and Sport, vol. 9, no. 7, July 2019, pp. 699-02, https://apcz.umk.pl/JEHS/article/view/7178.