Optimi (Online Predicative Tools For Intervention In Mental Illness). Biofeedback Based On Heart Rate Variability As A Preventive Tool Against Stress-Related Disorders. Psihìatr. nevrol. med. psihol. 2016;2(2 (4):48–52. Accessed October 25, 2026. https://periodicals.karazin.ua/pnmp/article/view/6231