TY JOUR TI MODELING OF THE WHEAT QUALITY INDICES WITH THE HELP OF ECONOMETRIC EQUATIONS SYSTEMS KW modeling KW spring soft wheat KW equation system KW quality KW variety KW fertilizers JO Bulletin of KSAU AU Gorodov, A.A. AU Gorodova, L.V. AU Plekhanova, L.V. PY 2014 IS PB Krasnoyarsk State Agrarian University