Umair Farukh, Sajid Hussain, Owais Qaisar, Ayesha Sardar, Muhammad Umair and Sher Zamir 2023. Vitamin D Status, Bone Mineral Density, and Functional Exercise Capacity in Patients with Chronic Obstructive Pulmonary Disease. Pakistan Journal of Chest Medicine. 29, 2 (Jun. 2023), 157–162.