Larsen GL, Morgan W, Heldt GP, Mauger DT, Boehmer SJ, Chinchilli VM, Lemanske RF, Martinez F, Strunk RC, Szefler SJ, Zeiger RS, Taussig LM, Bacharier LB, Guilbert TW, Radford S, Sorkness CA. Impulse oscillometry versus spirometry in a long-term study of controller therapy for pediatric asthma. J Allergy Clin Immunol. 2009 Apr; 123(4):861-7.e1.