1. Department of Statistics & Laboratory of Statistical Methodology, Athens University of Economics and Business Athens, Athens, Greece
2. Université de Nantes & LS2N UMR CNRS 6004, Nantes, France
3. Department of Statistics & Actuarial-Financial Mathematics, University of the Aegean, Karlovasi, Greece
4. Department of Business Administration, University of Piraeus, Piraeus, Greece