Sudnitsina D, Cherevichko A. Estimation of River Utroya Ecological State in Intensive Organic Pollution Area Using Plankton Communities ’ Characteristics (Pskov Region). ETR [Internet]. 2015 Aug. 9 [cited 2024 Dec. 4];3:62-4. Available from: https://journals.rta.lv/index.php/ETR/article/view/882