TY JOUR TI Validation of the design of milling type machines for receiving biofuel in the conditions of the woods of steppe and forest-steppe zones of the Volga region KW chips KW milling machine type KW conical mill KW grinding logging residues and stumps JO Actual directions of scientific researches of the XXI century: theory and practice AU Fokin, S.. PY 2014 IS 2 PB FSBE Institution of Higher Education Voronezh State University of Forestry and Technologies named after G.F. Morozov