@article{ref1,
title="Anhydrous ammonia, NH3",
journal="American Industrial Hygiene Association journal",
year="1971",
author="",
volume="32",
number="2",
pages="139-142",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0002-8894",
doi="",
url="http://dx.doi.org/"
}