Porcari, J. P., K. Falck-Wiese, S. Suckow-Stenger, J. Turek, A. Wargowsky, M. L. Cress, S. T. Doberstein, C. J. Hahn, A. L. Ryskey, and C. Foster. “COMPARISON OF THE TALK TEST AND PERCENT HEART RATE RESERVE FOR EXERCISE PRESCRIPTION”. Kinesiology, vol. 50, no. 1, June 2018, pp. 3-10, https://hrcak.srce.hr/ojs/index.php/kinesiology/article/view/6321.