Farooq, M., Kazmi, S. K. S., Shahzad, M., Fatima, S., Humerah, S. and Asad, J. (2023) “Correlation Between Vitamin D3 Levels and Glutathione in COVID-19 Patients: Evaluating Antioxidant Defense and Immune Response”, Pakistan Journal of Chest Medicine, 29(1), pp. 89–95. Available at: https://www.pjcm.net/index.php/pjcm/article/view/908 (Accessed: 16December2025).