I. Bondarenko, “THE RELATION BETWEEN CLINICAL SIGNS, PARAMETERS OF HEART RATE VARIABILITY AND FUNCTION OF EXTERNAL BREATHING IN THE PATIENT WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE BEFORE AND AFTER THERAPY”, J. V. N. Karazin Khark. Nat. Univ., Ser. Med., no. 11, pp. 58-62, 1.