Czaprowski, Dariusz, Łukasz Stoliński, Andrzej Szczygieł, and Agnieszka Kędra. “Sedentary Behaviours of Girls and Boys Aged 7-15”. Polish Journal of Public Health 121, no. 3 (September 1, 2011): 248–252. Accessed September 9, 2025. https://czasopisma.umlub.pl/pjph/article/view/1989.