P. Samikulin, A. Gryaznikh, R. Kuchin, and N. Nenenko, “CHANGES IN HEART RATE VARIABILITY IN RESPONSE TO MUSCULAR LOAD AND THEIR CORRELATION WITH THE CONCENTRATION OF STEROID HORMONES IN YOUNG MALES WITH DIFFERENT TRAINING SPECIFICS”, hsm, vol. 18, no. 1, pp. 33-45, Feb. 2018.