TY JOUR TI MODELING OF PNEUMATIC DEVICES FOR MASSAGE OF THE UDDER OF SINGLE-CHAMBER TYPE HEIFERS KW heifers KW dairy KW iron KW combo KW massage device KW pressure JO Bulletin Samara State Agricultural Academy AU Kurochkin, A.A. AU Frolov, D.I. PY 2016 IS 1 PB Samara State Agrarian University