00523naa#a2200169#i#450# EN\\bibl\113088 20260118062242.7 2311-1402 20120325b2012####ek#y0engy0150####ca RUS RU Theoretical basis for recreation and tourism studies at various hierarchial levels Journal article Nizhnevartovsk Nizhnevartovsk State University 2012 5 с. Journal article local Oborin Matvey Sergeevich vestnik.nvsu.ru