RT Journal Article SR Electronic T1 A comprehensive graphic approach to peak flow "traffic light system" -interpretation JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP 961 OP 962 DO 10.1183/09031936.97.10040961 VO 10 IS 4 A1 Rothe, TB YR 1997 UL http://erj.ersjournals.com/content/10/4/961.abstract AB