00520naa#a2200169#i#450# EN\\bibl\113084 20260118200850.7 2311-1402 20120325b2012####ek#y0engy0150####ca RUS RU System approach in implementation of environmental and geoecological activities Journal article Nizhnevartovsk Nizhnevartovsk State University 2012 4 с. Journal article local Oborin Matvey Sergeevich vestnik.nvsu.ru