1. Faculty of Accounting and Finance, Stavropol State Agrarian University, 355017 Stavropol, Russia
2. Graduate School of Finance, Plekhanov Russian University of Economics, 117997 Moscow, Russia
3. School of Economics and Management, Harbin Engineering University, Harbin 150001, China
4. Faculty of Social and Cultural Service and Tourism, Stavropol State Agrarian University, 355017 Stavropol, Russia