1. Department of Psychology, University of Bari, Via Quintino Sella 268, 70100 Bari, Italy
2. Department of Special Education, University of Texas at Austin, Mail Code D 5300, Austin, TX 78712
3. ONE Research Institute, P.O. Box 4657, Midlothian, VA 23112
4. University of Tasmania, Hobart, Tasmania 7001, Australia
5. Lega F. D'Oro Research Center, Via Montecerno 1, 60027 Osimo, Italy
6. Department of Psychology, University of Leiden, P.O. Box 9555, 2300 RB, Leiden, the Netherlands