@article{ref1,
title="Crash Helmets For California",
journal="British medical journal: BMJ",
year="1991",
author="",
volume="302",
number="6791",
pages="1487-1487",
abstract="<p>[Abstract unavailable]</p>",
language="",
issn="0959-8138",
doi="",
url="http://dx.doi.org/"
}