@article{ref1,
title="Helmet use, helmet use laws, and motorcyclist fatalities",
journal="American journal of public health",
year="1981",
author="Wilks, A. and Zador, Paul L. and Watson, Ginger S.",
volume="71",
number="3",
pages="297-300",
abstract="Abstract unavailable.",
language="",
issn="0090-0036",
doi="",
url="http://dx.doi.org/"
}