@article{ref1,
title="Driving exposure: what does it mean? how is it measured?",
journal="Traffic safety research review",
year="1960",
author="Stewart, RG",
volume="4",
number="2",
pages="9-11",
abstract="<p>[Abstract unavailable]</p>",
language="",
issn="0564-0741",
doi="",
url="http://dx.doi.org/"
}