Biryukov, O.V. 2023. Hydrochemical analysis of surface water quality dynamics in the Oskil river. Visnyk of V. N. Karazin Kharkiv National University. Series Еcоlogy. 29 (Nov. 2023), 17-25. DOI:https://doi.org/10.26565/1992-4259-2023-29-02.