Мамешина, Маргарита. “Change in Indicators of the Development of Flexibility of Students 13–15 Years Old under the Influence of Differentiated Learning”. Slobozhanskyi Herald of Science and Sport, no. 1(75) (February 29, 2020): 35–40. Accessed May 6, 2024. https://journals.uran.ua/index.php/1991-0177/article/view/197929.