ISMATOVICH, K. B. Heart Rate Variability and its Determination in Students by the Express Method. American Journal of Pediatric Medicine and Health Sciences (2993-2149), [S. l.], v. 2, n. 4, p. 43–45, 2024. Disponível em: https://grnjournal.us/index.php/AJPMHS/article/view/4215. Acesso em: 6 jul. 2024.