KICHKIN, N. . Features of heart rate variability and heart rate in football referees of various qualification levels under competitive conditions. Theory and Practice of Physical Culture, [S. l.], n. 5, p. 47–48, 2026. Disponível em: http://www.tpfk.ru/index.php/TPPC/article/view/1677. Acesso em: 26 jul. 2026.