[1] University of Valencia,Unit of Public Health, Hygiene, and Environmental care. Department of Preventive Medicine
[2] CIBER actions - Epidemiology and Public Health,Research group CIBER CB06/02/0045
[3] Research Foundation. Hospital Universitario “Dr. Peset”,Unit of Clinical Research, Cartagena and Department of Paediatrics
[4] University of Murcia,Section of Paediatric Pneumo
[5] HRSA. Maternal and Child Health Bureau,Allergy
[6] Hospital Infantil 12 de Octubre,Department of Health Sciences
[7] Public University of Navarre,Department of Paediatrics
[8] Hospital of Basurto,Section of Epidemiology. Centre of Public Health
[9] Regional Ministry of Health,Department of Paediatrics
[10] Castellón,Department of Paediatrics
[11] Health Centre of Otero – Oviedo,Department of Paediatrics
[12] Hospital del Mar,Department of Paediatrics
[13] University of Valladolid,undefined
[14] Hospital Torrecárdenas,undefined
[15] Hospital de Donostia,undefined
[16] Foundation María José Jove,undefined
[17] Unidad de Salud Pública,undefined
[18] Higiene y Sanidad Ambiental,undefined
[19] Departamento de Medicina Preventiva y Salud Pública,undefined