1. Associate Professor, Department of Management, Faculty of Economics and Business, Universitas Muhammadiyah Sumatera Utara [Muhammadiyah University of North Sumatra], Indonesia
2. M.Si, Senior Lecturer, Department of Economics Development, Faculty of Economics and Business, Universitas Muhammadiyah Sumatera Utara [Muhammadiyah University of North Sumatra], Indonesia
3. M.Si, Senior Lecturer, Department of Management, Faculty of Economics and Business, Universitas Muhammadiyah Sumatera Utara [Muhammadiyah University of North Sumatra], Indonesia
4. Dr., Associate Professor, Department of Management, Faculty of Economics and Business, Universitas Muhammadiyah Sumatera Utara [Muhammadiyah University of North Sumatra]
5. Doctoral Program Student in Management Science, Faculty of Economics and Business, Universitas Padjadjaran [Padjadjaran University]; Faculty of Economics and Business, Universitas Muhammadiyah Sumatera Utara [Muhammadiyah University of North Sumatra]