Suleman, A., Abdullah, A., Ullah, R., Nisar, H., Iqbal, Z., Naz, S. and Maqsood, S. (2018) “Frequency of Pulmonary Hypertension in Chronic Obstructive Pulmonary Disease Patients”, Pakistan Journal of Chest Medicine, 23(4), pp. 151–55. Available at: https://pjcm.net/index.php/pjcm/article/view/484 (Accessed: 16January2026).