00548naa#a2200193#i#450# EN\\bibl\11928 20250106185848.1 1995-042X 20160616b2016####ek#y0engy0150####ca RUS RU Functions of ecological tourism Journal article CHERKIZOVO Russian State University of Tourism and Service 2016 13 с. Journal article local Rudyk Aleksandr Shestakova Elena Butova Tatyana Georgievna naukaru.ru