title: Helicopters.
authors.forename: A
authors.initials: A
authors.lastname: Wilson
authors.forename: F
authors.initials: F
authors.lastname: Cross
mesh_terms: D000401:Aircraft / Q000191:economics; D000552:Ambulances; D003362:Cost-Benefit Analysis; D004632:Emergency Medical Services / Q000191:economics; D006113:United Kingdom; D014481:United States