TY JOUR TI ARTICULATED VEHICLE PITCH STABILITY FOR TRANSPORTING THE FOREST FOOD PRODUCTS KW forest food production KW articulated vehicle KW hitch mechanism KW mountain slope KW movement KW breakdown KW stability JO Bulletin of KSAU AU Kholopov, V.N. AU Labzin, V.A. PY 2012 IS PB Krasnoyarsk State Agrarian University