Лобода [V. Loboda] В. С. “Features of Psychology-Physiology Factors, Providing Efficiency of Technical-Tactical Actions of Young Tennis Players 6–8 Years”. Slobozhanskyi Herald of Science and Sport, no. 2(35), Apr. 2013, pp. 87-91, https://journals.uran.ua/index.php/1991-0177/article/view/18404.