Shaheen, Saima, Anjum Humayun, Jahangir Zaib, Syed Muhammad Sajid Ali Bukhari, Madeeha Jadoon, and Kinza Sammar. “The Correlation Between Cytokines Imbalance and Vitamin D Level in Patients With Early Chronic Obstructive Pulmonary Disease (COPD) and the Role of Vitamin D in Pulmonary Disease”. Pakistan Journal of Chest Medicine 29, no. 2 (June 2, 2023): 192–198. Accessed March 8, 2026. https://pjcm.net/index.php/pjcm/article/view/838.