@article{ref1,
title="The use of "control groups" in highway accident research",
journal="Traffic safety research review",
year="1961",
author="Shumate, RP and Novak, JW",
volume="5",
number="",
pages="20-24",
abstract="<p>[Abstract unavailable]</p>",
language="",
issn="0564-0741",
doi="",
url="http://dx.doi.org/"
}