1. Mardin Artuklu University, Faculty of Tourism, Artuklu, Mardin, Turkey; Postdoctoral researcher, Department of Economics, Management, Industrial Engineering and Tourism, Research Unit of Governance, Competitiveness and Public Policies (GOVCOPP), University of Aveiro, Aveiro, Portugal
2. Varna University of Management, Varna, Bulgaria; Zangador Research Institute, Varna, Bulgaria