@article{ref1,
title="Letter: Nitrous-oxide asphyxia",
journal="Lancet",
year="1974",
author="Porter, K. R.",
volume="1",
number="7864",
pages="987-988",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0140-6736",
doi="",
url="http://dx.doi.org/"
}