TY  - RPRT
TI  - Helium/oxygen and severe COPD.
AU  - G Laden
PY  - 2001
DO  - 10.1016/s0140-6736(05)71710-4
UR  - https://pubmed.ncbi.nlm.nih.gov/11229699/
ID  - 11229699
ER  -