PT - JOURNAL ARTICLE AU - M. Gaga AU - E. Zervas AU - P. Chanez TI - Update on severe asthma: what we know and what we need AID - 10.1183/09059180.00001009 DP - 2009 Jun 01 TA - European Respiratory Review PG - 58--65 VI - 18 IP - 112 4099 - http://err.ersjournals.com/content/18/112/58.short 4100 - http://err.ersjournals.com/content/18/112/58.full SO - EUROPEAN RESPIRATORY REVIEW2009 Jun 01; 18