@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/" }