TY  - RPRT
TI  - Minimal clinically important difference--exacerbations of COPD.
AU  - Peter M A Calverley
PY  - 2005
DO  - 10.1081/copd-200050647
UR  - https://pubmed.ncbi.nlm.nih.gov/17136975/
ID  - 17136975
ER  -