RT Journal Article SR Electronic T1 Impact of changes in physical activity on health-related quality of life among patients with chronic obstructive pulmonary disease JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society DO 10.1183/09031936.00021409 A1 C. Esteban A1 J.M. Quintana A1 M. Aburto A1 J. Moraza A1 M. Egurrola A1 J. PĂ©rez-Izquierdo A1 S. Aizpiri A1 A. Urko A1 A. Capelastegui YR 2010 UL http://erj.ersjournals.com/content/early/2010/01/14/09031936.00021409.abstract AB