Popel’, S., G. Pyatnychuk, D. Pyatnichuk, V. Maystruv, V. Verboviy, N. Zemskaya, A. Kryzhanivskaya, and R. Chovgan. “Functional Systems of students’ Organism Depending on Physical Fitness to Physical Load”. Physical Education of Students, vol. 21, no. 6, Dec. 2017, pp. 302-9, doi:10.15561/20755279.2017.0607.