Dr Noor-Ul-Arfeen, Dr Ali Anwar, Dr Usman Ahmad Kamal, Dr Faizan Ali Khan, Dr Muhammad Mussab Aman, & Dr Aaiz Hassan. (2025). ASSOCIATION BETWEEN SERUM 25-HYDROXYVITAMIN D LEVELS AND FREQUENCY OF EXACERBATIONS IN CHRONIC OBSTRUCTIVE PULMONARY DISEASE PATIENTS. Journal of Population Therapeutics and Clinical Pharmacology, 32(6), 1975-1978. https://doi.org/10.69980/89wah281