“Comparative Characteristics of Physical Training Among Younger Adolescents in Secondary School”, Fiz. vihov. sport kul’t. zdor. suchas. susp., no. 4(32), pp. 76–78, Dec. 2015, Accessed: May 04, 2024. [Online]. Available: https://sport.vnu.edu.ua/index.php/sport/article/view/76