TY JOUR TI INFLUENCE OF THE TRACTORS’ OPERATION LEVEL ON ITS RELIABILITY INDICATORS IN AGRICULTURAL PRODUCTION KW level of operation KW operating conditions KW resource consumption KW annual operating time KW efficiency increase. JO Vestnik of Kazan State Agrarian University AU Galiev, I.G. AU Khusainov, R.. AU Husainova, T.A. AU Sitdikov, F.F. AU Pikmullin, G.V. AU Bulgariev, G.G. PY 2018 IS 13 PB Kazan state agrarian University