Kadir, Yolanda, and Povi P. Indarta. “Vitamin D Supplementation to Reduce Chronic Obstructive Pulmonary Disease Exacerbation: A Scoping Review”. International Journal of Advances in Medicine 12, no. 2 (February 21, 2025): 250–256. Accessed December 27, 2025. https://www.ijmedicine.com/index.php/ijam/article/view/4205.