@article{ref1,
title="A study of the relationship of street-level carbon monoxide concentrations to traffic accidents",
journal="Traffic safety research review",
year="1960",
author="Clayton, G. D. and Cook, W. A. and Fredrick, W. G.",
volume="4",
number="4",
pages="25-31",
abstract="<p>[Abstract unavailable]</p>",
language="",
issn="0564-0741",
doi="",
url="http://dx.doi.org/"
}