RT Journal Article SR Electronic T1 Household air pollution as an important factor in the complex relationship between altitude and COPD JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP 1802454 DO 10.1183/13993003.02454-2018 VO 53 IS 2 A1 Xavier BasagaƱa YR 2019 UL http://erj.ersjournals.com/content/53/2/1802454.abstract AB