For citations:
Trifonova T.A., Chesnokova S.M., Savelev O.V. Evaluation of the trophic level and self-cleaning ability of small flows by hydrochemical indicators (through the example of the Rpen River). South of Russia: ecology, development. 2021;16(2):88-97. (In Russ.) https://doi.org/10.18470/1992-1098-2021-2-88-97