Ahmad, Rehan, et al. “PATTERNS OF PRESENTATION OF CHRONIC ISCHEMIC HEART DISEASE WITH AND WITHOUT PREVIOUS MYOCARDIAL INFARCTION”. Journal of Ayub Medical College Abbottabad, vol. 21, no. 4, Dec. 2009, pp. 143-5, https://jamc.ayubmed.edu.pk/index.php/jamc/article/view/3166.