1. Department of Pulmonology, Allergology and Immunology; Children's Hospital Zagreb; Zagreb Croatia
2. Otorhinolaryngology Department; Children's Hospital Zagreb; Zagreb Croatia
3. Referral Centre for Paediatric Gastroenterology and Nutrition; Children's Hospital Zagreb; Zagreb Croatia
4. University of Zagreb School of Medicine; Zagreb Croatia
5. University J.J. Strossmayer School of Medicine Osijek; Osijek Croatia