1. Department of Economics, Democritus University of Thrace, 69100 Komotini, Greece
2. School of Social Sciences, Business & Organisation Administration, Hellenic Open University, Par. Aristotelous 18, 26335 Patras, Greece
3. Department of Organization Management, Marketing and Tourism, School of Economics and Management, International Hellenic University, Thessaloniki Campus, 17 Km Thessaloniki-Sindos, 57400 Thessaloniki, Greece