TY  - RPRT
TI  - COPD exacerbations . 2: aetiology.
AU  - E Sapey
AU  - R A Stockley
PY  - 2006
DO  - 10.1136/thx.2005.041822
UR  - https://pubmed.ncbi.nlm.nih.gov/16517585/
ID  - 16517585
ER  -