Geographic variation in the prevalence of asthma symptoms in Spanish children and adolescents. International Study of Asthma and Allergies in Childhood (ISAAC) Phase 3, Spain
Centro de Salud de Las Vegas, Area Sanitaria III. Avilés, Servicio de Salud del Principado de Asturias, Asturias, Spain. ignacio,carvajal@sespa.printcast.es