Nikolaychuk , M., . L. Shostakovych-Koretskaya, I. Budayeva, and S. . Biletska. “Influence of Seasonality on Vitamin D Level in Patients With HCV Infection and Healthy People”. Medicni Perspektivi, vol. 26, no. 1, Mar. 2021, pp. 184-90, doi:10.26641/2307-0404.2021.1.228000.