00592naa#a2200193#i#450# EN\\bibl\10564 20241202190828.1 2073-0462 20151225b2015####ek#y0engy0150####ca RUS RU OPTIMIZATION OF SOWN AREA STRUCTURE OF CROPS BY ECONOMIC AND MATHEMATICAL MODELING: PRACTICAL ASPECT Journal article Kazan Kazan state agrarian University 2015 3 с. Journal article local Nuretdinova Yuliya Nuretdinov Ildar Khasyanov Oleg naukaru.ru