School of Economics and Management, China University of Geosciences, Wuhan, China 
                                            
                                            School of Economics and Management, China University of Geosciences, Wuhan, China 
                                            
                                            School of Economics and Management, China University of Geosciences, Wuhan, China 
                                            
                    
                          
                 Copyright ©    Bing  Gong, Xian-feng  Zhang, Chuan-min  Shuai  et al. This is 
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