Effects on small airway obstruction of long-term treatments with beclomethasone/formoterol hydrofluoroalkane (metered-dose inhaler) versus fluticasone/salmeterol (dry-powder inhaler) in asthma: a preliminary study. - Corda L; Gardenghi GG; Modina D; Montemurro LT; Novali M; Tantucci C (Allergy and asthma proceedings, 2011)