Mrozkowiak, Mirosław, Marek Sokołowski, Alicja Kaiser, and Mariusz Posłuszny. 2018. “The Incidence of Significant Relationships Between Selected Parameters of Feet and Parameters of Trunk in Children Aged 4, 5 and 6 Years”. Journal of Education, Health and Sport 8 (2):320-33. https://apcz.umk.pl/JEHS/article/view/5334.