TY JOUR TI MATHEMATICAL MODEL OF ESTIMATION THE DYNAMIC PARAMETERS OF MACHINE AND TRACTOR UNIT’S ENGINE UNDER UNSTEAD LOAD KW Engine performance of machine and tractor unit KW unsteady load KW mathematical model JO Vestnik of Kazan State Agrarian University AU Medvedev, V.M. AU Sinickiy, S.A. PY 2019 IS 14 PB Kazan state agrarian University