1. College of Economics and Management, Research Center for Soft Energy Science Nanjing University of Aeronautics and Astronautics Nanjing China
2. IESEG School of Management Univ. Lille, CNRS, UMR 9221 ‐ LEM ‐ Lille Economie Management Lille France
3. School of Statistics and Applied Mathematics Anhui University of Finance and Economics Bengbu China