@article{ref1,
title="Various types of intra and extra oral mouth guards",
journal="Oral health",
year="1970",
author="",
volume="60",
number="5",
pages="8-9",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0030-4204",
doi="",
url="http://dx.doi.org/"
}