00657naa#a2200181#i#450# EN\\bibl\16048 /en/manage/index 20250604000547.3 1993-7768 20170620b2017####ek#y0engy0150####ca RU STUDY OF IRRATIONAL SYSTEMS BY EXTENDING THE LOGICAL-MATHEMATICAL APPARATUS Journal article CHERKIZOVO Russian State University of Tourism and Service 2017 8 с. Journal article local Туристско-экскурсионное обслуживание. 71.37 grnti Kortunov Vadim Vadimovich test.editorum.ru /en/manage/index