Sreekumar, A., and K. K. Velayudhan. “Role of Serum Magnesium in Acute Exacerbations of Chronic Obstructive Pulmonary Disease”. International Journal of Advances in Medicine, vol. 8, no. 4, Mar. 2021, pp. 505-10, doi:10.18203/2349-3933.ijam20210994.