Khatun, U. F. ., Zerin, A. ., & Barua, U. K. . (2022). Status of Vitamin D among Patients Admitted with Acute Exacerbation of COPD in Cox’s Bazar Medical College Hospital. Journal of Medicine, 23(2), 121–125. https://doi.org/10.3329/jom.v23i2.60628