TY JOUR TI OBTAINING FULVIC ACIDS FROM LEONARDITE KW leonardite KW extraction KW process parameters KW fulvic acids KW yield of fulvic acids from leonardite JO Bulletin of KSAU AU Velichko, N.A. AU Bondar', I.V. AU Smol'nikova, Y.V. AU Stutko, O.V. PY 2024 IS 0 PB Krasnoyarsk State Agrarian University