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 Esteban, C. A1 Quintana, J.M. A1 Aburto, M. A1 Moraza, J. A1 Egurrola, M. A1 Pérez-Izquierdo, J. A1 Aizpiri, S. A1 Urko, A. A1 Capelastegui, A. YR 2010 UL http://erj.ersjournals.com/content/early/2010/01/14/09031936.00021409.abstract AB