@article{ref1,
title="Motorcycle helmet use, incidence of head injury, and cost of hospitalization",
journal="Journal of emergency nursing",
year="1989",
author="May, C. and Morabito, D.",
volume="15",
number="5",
pages="389-392",
abstract="Abstract unavailable.",
language="",
issn="0099-1767",
doi="",
url="http://dx.doi.org/"
}