MATCZAK, Dawid and WIECZOREK, Marta. Assessing the effectiveness of learning a complex motor activity in children aged 9-10 years. Journal of Education, Health and Sport. Online. 16 June 2022. Vol. 12, no. 6, pp. 158-169. [Accessed 5 February 2025]. DOI 10.12775/JEHS.2022.12.06.016.