Shahzad, Khurram, et al. “DIRECT STENTING VERSUS BALLOON PRE-DILATATION IN ELECTIVE PERCUTANEOUS CORONARY INTERVENTION”. Journal of Ayub Medical College Abbottabad, vol. 32, no. 2, May 2020, pp. 259-62, https://www.jamc.ayubmed.edu.pk/index.php/jamc/article/view/7290.