Mohammad Reza Masjedi, Lida Fadaizadeh, Katayoon Najafizadeh, Pouneh Dokouhaki. Prevalence and Severity of Asthma Symptoms in Children of Tehran- International Study of Asthma and Allergies in Childhood (ISAAC). Iran J Allergy Asthma Immunol. 1;3(1):25-30.