Author(s): |
Liqin Liu, Beijing Jiaotong University, School of Economics & Management, Beijing, Peoples R China, 100044 Lijie Yang, Beijing Jiaotong University, School of Economics & Management, Beijing, Peoples R China, 100044 Yisheng Liu, Beijing Jiaotong University, School of Economics & Management, Beijing, Peoples R China, 100044 |