Martynenko, Oleksandr, Gianfranco Raimondi, Luca Barsi, and Liudmila Maliarova. “Entropy of Frequency Domain of Heart Rate Variability”. The Journal of V. N. Karazin Kharkiv National University, series "Medicine", no. 45 (November 28, 2022). Accessed April 18, 2024. https://periodicals.karazin.ua/medicine/article/view/21057.