1. DISA-MIS, University of Salerno, 84084 Fisciano, Italy
2. A2VI-Lab, DISIM, University of L’Aquila, 67100 L’Aquila, Italy
3. A2VI-Lab, DIIIE, University of L’Aquila, 67100 L’Aquila, Italy
4. A2VI-Lab, c/o Department of MESVA, University of L’Aquila, 67100 L’Aquila, Italy