Laxman Kumar Soni, Priyanka Soni, Daljeet Kaur, C. R. Choudhary, & K.C. Agarwal. (2022). Correlation of vitamin D deficiency with frequent exacerbations in COPD patients at tertiary care hospital in western Rajasthan. International Journal of Health and Clinical Research, 5(1), 586–588. Retrieved from https://www.ijhcr.com/index.php/ijhcr/article/view/4709