TY JOUR TI Modern approaches to mathematical modeling of economic development KW mathematical modeling KW economic development KW macroeconomic models KW fuzzy models KW intelligent systems KW digital economy KW forecasting JO Journal of Applied Research AU Galushkin, V.V. AU Morzheedov, V.G. AU Skosareva, E.P. PY 2026 IS 0 PB ITBO University