%0 Journal Article %T ASSESSMENT OF HEAVY METALS CONCENTRATION FE, ZN, CD, AND PB IN NATURAL WATER SOURCES %A Flefel', H.E. %A Gutova, M.O. %A Donnik, I.M. %A Gribovskiy, Y.G. %K %J Agrarian Bulletin of the %D 2019 %N 185 %P 3 %I Ural State Agrarian University