RT Journal Article SR Electronic T1 Update on severe asthma: what we know and what we need JF European Respiratory Review JO EUROPEAN RESPIRATORY REVIEW FD European Respiratory Society SP 58 OP 65 DO 10.1183/09059180.00001009 VO 18 IS 112 A1 M. Gaga A1 E. Zervas A1 P. Chanez YR 2009 UL http://err.ersjournals.com/content/18/112/58.abstract AB