RT Journal Article SR Electronic T1 Severe exacerbations predict excess lung function decline in asthma JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society DO 10.1183/09031936.00165106 A1 T.R. Bai A1 J.M. Vonk A1 D.S. Postma A1 H.M. Boezen YR 2007 UL http://erj.ersjournals.com/content/early/2007/05/30/09031936.00165106.abstract AB