TY  - RPRT
TI  - Is asthma really changing?
AU  - P P Van Asperen
PY  - 1987
DO  - 10.1111/j.1440-1754.1987.tb00269.x
UR  - https://pubmed.ncbi.nlm.nih.gov/3326573/
ID  - 3326573
ER  -