@article{ref1,
title="Carbon monoxide as a hazard in aviation",
journal="Journal of Occupational Medicine",
year="1973",
author="Howlett, L. and Shephard, R. J.",
volume="15",
number="11",
pages="874-877",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0096-1736",
doi="",
url="http://dx.doi.org/"
}