1. Center for Adolescent Medicine and UNESCO Chair on Adolescent Health Care; First Department of Pediatrics; School of Medicine; National and Kapodistrian University of Athens, ‘Aghia Sophia’ Children's Hospital; Athens Greece
2. Adolescent Health Unit; Second Department of Pediatrics; School of Medicine National and Kapodistrian University of Athens; ‘P. and A. Kyriakou’ Children's Hospital; Athens Greece