1. Department of Paediatric Respiratory Diseases and Allergy The Medical University of Warsaw Warsaw Poland
2. Department of Otorhinolaryngology and Audiology CEMIC Institute Buenos Aires Argentina
3. Department of Otorhinolaryngology Lusíadas Hospital Porto Portugal
4. Department of Otorhinolaryngology National Institute of Pediatrics Cuicuilco Mexico
5. Master of Science Program Postgraduate UnitFaculty of Medicine National University of Mexico Cuicuilco Mexico