Boiaryn, M. V., V. U. Voloshyn, and O. O. Tsos. “Ecological Condition of the Sapalayivka River in the Conditions of Lutsk Urbosystem”. Visnyk of V. N. Karazin Kharkiv National University. Series Еcоlogy, no. 23, Nov. 2020, pp. 21-29, doi:10.26565/1992-4259-2020-23-02.