Autori:
1. Silvana Žežova, University “Goce Delčev”, Štip, Faculty of Technology, Macedonia
2. Vineta Srebrenkoska, University “Goce Delčev”, Štip, Faculty of Technology, Macedonia
3. Svetlana Risteska, University of St.Kliment Ohridski Bitola, Faculty of Economics - Prilep, Macedonia
4. Sanja Risteski, Univerzitet “Goce Delčev”, Štip, Tehnološko –tehnički fakultet, Macedonia