Shlyk, N. “HEART RATE VARIABILITY STANDARDS AT REST AND ORTHOSTASIS AT DIFFERENT MxDMn VALUES AND THEIR CHANGE IN BIATHLETES DURING THE TRAINING PROCESS”. Human. Sport. Medicine 20, no. 4 (January 29, 2021): 5-24. Accessed September 28, 2025. https://hsm.susu.ru/hsm/en/article/view/1111.