P. J. . Osredkar, “The COVID-19 Pandemic, Seasons and the Vitamin D Laboratory Strategy”, IJSBAR, vol. 56, no. 2, pp. 182–189, Mar. 2021, Accessed: Nov. 21, 2025. [Online]. Available: https://www.gssrr.org/JournalOfBasicAndApplied/article/view/12287