00534naa#a2200181#i#450# EN\\bibl\766 20250106155436.1 1993-7768 20131211b2013####ek#y0engy0150####ca RUS RU Service as a Key to Analyzing the Causes of Global Crisis Journal article CHERKIZOVO Russian State University of Tourism and Service 2013 7 с. Journal article local Fedulin Aleksandr Bagdasaryan Vardan E. naukaru.ru