Azizan, A., and F. M. Sakri. “Experimental Study to Investigate the Effect of Whole-Body Vibration Using Steering Entropy As a Function of Drowsiness”. International Journal of Advanced Science and Technology, Vol. 28, no. 8s, Oct. 2019, pp. 158 -62, http://sersc.org/journals/index.php/IJAST/article/view/866.