Dudek, J., M. Chuchla, S. Snela, D. Szymczyk, and M. Drużbicki. “Disorders of gait pattern in children with cerebral palsy”. European Journal of Clinical and Experimental Medicine, vol. 7, no. 3, Sept. 2009, pp. 317–322, https://journals.ur.edu.pl/ejcem/article/view/13163.