1. College of Tourism and Service Management, Nankai University, Tianjin, China
2. College of Business and Public Management, Wenzhou-Kean University, Ouhai, People's Republic of China
3. School of Tourism, Hainan University, Haikou, People's Republic of China
4. Sustainable Development Study Center, Government College University, Lahore, Pakistan
5. MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin, China