Antretter, Markus, Sebastian Färber, Lorenz Immler, Matthias Perktold, Doris Posch, Christian Raschner, Felix Wachholz, and Martin Burtscher. “The Hatfield-System Versus the Weekly Undulating Periodised Resistance Training in Trained Males: Effects of a Third Mesocyle”. Journal of Human Sport and Exercise 14, no. 3 (September 2, 2019): 599–607. Accessed April 24, 2024. https://www.jhse.ua.es/article/view/2019-v14-n3-hatfield-system-weekly-undulating-periodised-resista.