1. Politehnica Univ. of Bucharest,Dept. of Automatic Control & Systems Eng,Bucharest,Romania,060042
2. University of Groningen, Nettelbosje 2,Faculty of Economics and Business,Department of Economics, Econometrics and Finance,Groningen,The Netherlands,9747 AE
3. University Politehnica Bucharest,Department of Automatic Control and Systems Engineering,Bucharest,Romania,060042