@misc{indiciaeb1d153eb0e78,
  title = {1990 helipad survey.},
  author = {H M Collett},
  year = {1990},
  doi = {10.1016/s1046-9095(05)80437-4},
  url = {https://pubmed.ncbi.nlm.nih.gov/10106059/},
  note = {Source identifier: 10106059}
}