Зюзь [Zuz Volodymyr] В. М. “Becoming and Maintainance of Sporting Form As a Criterion of Sporting Achievement”. Slobozhanskyi Herald of Science and Sport, no. 5-2(33), Dec. 2012, pp. 57-61, https://journals.uran.ua/index.php/1991-0177/article/view/21597.