TY JOUR TI MATHEMATICAL MODEL OF INTERACTION OF FREE ROLLING FLAT DISK WITH SOIL KW mathematical model KW free-spinning disk KW interaction with soil KW soil reactions KW power characteristics. JO Vestnik of Kazan State Agrarian University AU Akimov, A.P. AU Konstantinov, Y.V. AU Mazyarov, V.P. PY 2018 IS 13 PB Kazan state agrarian University