TY JOUR TI THE THEORETICAL SUBSTANTIATION OF THE PICK-UP PLATFORM PPK-4 WORK PARAMETERS AND MODES FOR CEREAL CROP HARVESTING KW pick-up platform KW operating mode KW conveyer line KW kinematic mode KW cereal crops KW harvesting KW crop losses JO Bulletin of KSAU AU Sobachkin, A.L. PY 2013 IS PB Krasnoyarsk State Agrarian University