TY JOUR TI Simulation of operation of forestry disc ripper in the composition of machine and tractor unit KW machine and tractor unit KW disk ripper KW САD KW wood cuttings down KW stony soils KW analysis. JO Actual directions of scientific researches of the XXI century: theory and practice AU Shabanov, M.L. AU Lysych, M.N. AU Ikonnikov, R.. PY 2015 IS 3 PB FSBE Institution of Higher Education Voronezh State University of Forestry and Technologies named after G.F. Morozov