@article{ref1,
title="Loudness display for accurate aerospace instrument flying",
journal="Aerospace medicine",
year="1968",
author="Hattler, K. W.",
volume="39",
number="7",
pages="688-692",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0001-9402",
doi="",
url="http://dx.doi.org/"
}