TY JOUR TI MODIFICATION OF MODERN MONEY AND ITS FUNCTIONS KW concept of money KW essence of money KW modern economy KW theory of money KW digitalization of payments JO Trade, service, food industry AU Demchenko, O.S. AU Demchenko, S.K. AU Melnikov, P.Y. AU Pleshakova, V.R. PY 2025 IS 5 PB Siberian Federal University