RT Journal Article SR Electronic T1 Excess mortality in patients with asthma on long-acting β2-agonists JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP 900 OP 902 DO 10.1183/09031936.00085606 VO 28 IS 5 A1 J. Hasford A1 J. C. Virchow YR 2006 UL http://erj.ersjournals.com/content/28/5/900.abstract AB