Hamdan, Abdullah Ghazi, and Usama Altay. “A Comparative Study of SEMG Signal of the Symmetrical Pectoral Major Muscle in Bench Press Exercise Using Smith Machine and Free Weights”. Journal of Physical Education, vol. 32, no. 2, June 2020, pp. 1-7, https://doi.org/10.37359/JOPE.V32(2)2020.984.