Batkunde, Y. A. ., M. . Ilyas, I. . Djaharuddin, N. A. . Tabri, H. . Iskandar, and A. . Santoso. “Analysis of Vitamin D Levels on Bronchiectasis Severity”. Respiratory Science, vol. 1, no. 2, Feb. 2021, pp. 88-97, doi:10.36497/respirsci.v1i2.11.