TY JOUR TI Accounting of income and expenses under the simplified taxation system KW accounting KW income KW expenses KW small and medium-sized businesses KW value added tax KW simplified taxation system JO JOURNAL OF MONETARY ECONOMICS AND MANAGEMENT AU Sharapova, V.M. AU Sharapov, Y.V. AU Kaletina, E.Y. PY 2026 IS 0 PB ITBO University