Riaz, Bushra, et al. “CORRELATION OF SIGNAL AVERAGED ECG PARAMETERS WITH LEFT VENTRICULAR MASS INDEX IN PATIENTS WITH SYSTEMIC ARTERIAL HYPERTENSION”. Pakistan Journal of Physiology, vol. 14, no. 1, Mar. 2018, pp. 19-22, https://pjp.pps.org.pk/index.php/PJP/article/view/155.