Darbar, S., S. Agarwal, and S. Saha. “Maintaining Vitamin D Balance to Mitigates COVID-19 Infection and Boosting Immune System”. INTERNATIONAL JOURNAL OF PHARMACEUTICAL EDUCATION AND RESEARCH (IJPER), Vol. 3, no. 02, Nov. 2021, pp. 45-50, https://ijper.in/index.php/IJPER/article/view/124.