RT Journal Article SR Electronic T1 Medical therapy for COPD: lessons from the real world JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP 797 OP 798 DO 10.1183/09031936.02.00405402 VO 20 IS 4 A1 P.M.A. Calverley YR 2002 UL http://erj.ersjournals.com/content/20/4/797.abstract AB