1. Petroleum-Gas University of Ploiesti, Ploiesti, Prahova, Romania
2. National Institute for Economic Research ‘Costin C. Kiritescu’, Romanian Academy, Bucharest, Romania
3. The Bucharest University of Economic Studies, Bucharest, Romania
4. Faculty of Economics, Doctoral School, University Valahia of Targoviste, Romania
5. European Marketing and Management Association, Banja Luka, Bosnia and Herzegovina