Khan, Dr. Muhammad Nadir, et al. “OUTCOMES OF SUCCESSFUL VERSUS UNSUCCESSFUL PERCUTANEOUS CORONARY INTERVENTION IN CHRONIC TOTAL OCCLUSIONS: A TWO YEAR STUDY”. Pakistan Armed Forces Medical Journal, vol. 69, no. Suppl 1, May 2019, pp. S138-40, https://pafmj.org/PAFMJ/article/view/2848.