Petroleum & Gas University, affiliation not provided to SSRN and University of Suceava - Stefan cel Mare

Bucharest University of Economic Studies, University of Tg-Jiu, University of Piraeus, University Constantin Brancusi of Targu-Jiu, Petroleum & Gas University, Bucharest Academy of Economic Studies, Bucharest Academy of Economic Studies, University of Craiova - Faculty of Law and Administrative Sciences, Spiru Haret University, Spiru Haret University, University of Pitesti, University of Tg-Jiu, University Constantin Brancusi of Targu-Jiu, University Constantin Brancusi of Targu-Jiu, University Constantin Brancusi of Targu-Jiu, Gorj County Hospital, Gorj County Hospital, University Constantin Brancusi of Targu-Jiu, Constantin Brancusi University of Targu Jiu, Bucharest Academy of Economic Studies and Free International University of Moldova

affiliation not provided to SSRN, Petroleum & Gas University and University of Suceava - Stefan cel Mare

Petroleum & Gas University