A. Kulik, O. Zaderykhin, V. Shulgin, A. Martynenko, and IabluchanskyiМ., “CAPTURE AND WITHHOLDING OF HEART RATE VARIABILITY INDEXES WITH PACED BREATHING IN HEALTHY VOLUNTEERS”, J. V. N. Karazin Khark. Nat. Univ., Ser. Med., no. 19, pp. 46-52, 1.