@article{ref1,
title="Audiometer modification and pulse-tone technique for pure-tone threshold determination",
journal="Aerospace medicine",
year="1969",
author="Bragg, V. C. and Collins, F. G.",
volume="40",
number="1",
pages="9-11",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0001-9402",
doi="",
url="http://dx.doi.org/"
}