@article{ref1,
title="Flight helmets: how they work and why you should wear one",
journal="Journal of air medical transport",
year="1992",
author="Crowley, J. S. and Licina, J. R. and Bruckart, J. E.",
volume="11",
number="8",
pages="19-23, 26",
abstract="Abstract unavailable.",
language="",
issn="1046-9095",
doi="",
url="http://dx.doi.org/"
}