TY JOUR TI Selective statistical estimates of multi-year monthly concentrations of biogenous pollution of small rivers of the Northwest zone of the Russian Federation KW Non-chernozem zone of the Russian Federation KW hydrochemical monitoring of the environment KW small rivers KW biogenes KW statistical processing KW correlation and autocorrelation analysis. JO Melioration and Water Management AU Kovalenko, S.N. PY 2020 IS 2019 PB ANO Editorial Board Melioration and water management