TY  - RPRT
TI  - Screening for chronic obstructive pulmonary disease.
AU  - O J Balchum
PY  - 1968
DO  - 10.1080/00039896.1968.10665150
UR  - https://pubmed.ncbi.nlm.nih.gov/5654544/
ID  - 5654544
ER  -