Pavol, B.     The reversibility of muscular system of children 9-10 years old [Текст] / B. Pavol, S. Adamcak, M. Nemec // Olympic Sports and Sport for All. Sport, Stress, Adaptation : proceeding book of XVI International Scientific Congress and VI International Scientific Congress (17-19 May 2012 ) : extra issue of Sport and science / ed. staff: P. Gashev, D. Dasheva, S. Videnova ; National Sport Academy "Vassil Leski". — Sofia, 2012. — P. 217-220.