TY JOUR TI Public-private partnership in infrastructure projects: a legal model and an assessment of economic efficiency KW public-private partnership KW infrastructure projects KW legal model KW efficiency assessment KW risk allocation KW Federal Law No. 224-FZ JO Journal of Applied Research AU Abdullaeva, Z.M. AU Batashev, R.V. AU Suleymanova, M.G. PY 2026 IS PB ITBO University