Authors
Ion Simaciu
Retired lecturer, Petroleum-Gas University of Ploieşti, Ploiești, Romania
Zoltan Borsos
Petroleum-Gas University of Ploieşti, Ploiești, Romania
Viorel Drafta
Independent researcher
Gheorghe Dumitrescu
High School Toma N. Socolescu, Ploiești, Romania