1. School of Statistics, Xi’an University of Finance and Economics, Xi’an 710100, People’s Republic of China
2. Xi’an University of Finance and Economics, China (Xi’an) Institute for Silk Road Research, Xi’an 710100, People’s Republic of China
3. Division of Dynamics, Lodz University of Technology, Stefanowskiego 1/15, 90-924 Lodz, Poland