1. 1st Department of Pediatrics Hippokratio General Hospital Aristotle University of Thessaloniki Thessaloniki Greece
2. University of Nicosia Medical School Nicosia Cyprus
3. Pulmonology Private Practice Thessaloniki Greece
4. Department of Paediatrics Medical School Democritus University of Thrace Alexandroupolis Greece
5. Department of Paediatric Respiratory and Sleep Medicine Royal Hospital for Sick Children Edinburgh UK
6. 3rd Department of Medicine Papageorgiou Hospital Aristotle University of Thessaloniki Greece