RT Journal Article SR Electronic T1 The minimal clinically important difference of the Severe Respiratory Insufficiency questionnaire in severe COPD JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP 2001334 DO 10.1183/13993003.01334-2020 VO 56 IS 6 A1 Tim Raveling A1 Janine Kort A1 Gerrie Bladder A1 Wolfram Windisch A1 Peter J. Wijkstra A1 Marieke L. Duiverman YR 2020 UL http://erj.ersjournals.com/content/56/6/2001334.abstract AB