Ali, B., I. . Shah, A. . Ali, E. . Rehman, M. K. . Khan, and H. . Hakim. “Undiagnosed Chronic Obstructive Pulmonary Disease Amongst Coronary Artery Disease Patients: A Single Centre Study”. Pakistan Journal of Chest Medicine, vol. 28, no. 4, Dec. 2022, pp. 414-9, doi:10.1996/pjcm.v28i4.879.