Baig, Amna, Shazia Siddiq, Mehwish Rasheed Butt, and Sabah Salik. 2025. “Association of Serum Vitamin D Levels in Acute Exacerbation of COPD”. Indus Journal of Bioscience Research 3 (5): 1010-14. https://doi.org/10.70749/ijbr.v3i5.2209.