Stepanova, N., V. Driianska, L. Korol, L. Snisar, and S. Savchenko. “Pre-Existing Serum Indoxyl Sulfate and COVID-19 Outcomes in Patients Undergoing Hemodialysis: A Retrospective Cohort Study”. Ukrainian Journal of Nephrology and Dialysis, no. 2(78), May 2023, pp. 61-68, doi:10.31450/ukrjnd.2(78).2023.07.