TY  - RPRT
TI  - 1990 helipad survey.
AU  - H M Collett
PY  - 1990
DO  - 10.1016/s1046-9095(05)80437-4
UR  - https://pubmed.ncbi.nlm.nih.gov/10106059/
ID  - 10106059
ER  -