@article{ref1,
title="Etiology and treatment of post concussion syndrome",
journal="Headache",
year="1968",
author="Gilbert, M. M.",
volume="8",
number="2",
pages="57-61",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0017-8748",
doi="",
url="http://dx.doi.org/"
}