Institution: | 1. Department of Mathematics, Inner Mongolia University of Technology, Hohhot 010051, PR China;2. Jining Teachers College, Wulanchabu 012000, Inner Mongolia, PR China;3. College of Science, Shanghai Institute of Technology, Fengxian District, Shanghai 201418, PR China;1. Department of International and European Economic Studies, Athens University of Economics and Business, Athens 10434, Greece;2. Department of Economics, University of Piraeus, Karaoli & Dimitriou 80, Piraeus 18534, Greece |