@article{ref1,
title="Post traumatic headache",
journal="Military medicine",
year="1958",
author="Allerton, W. S.",
volume="123",
number="2",
pages="126-130",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0026-4075",
doi="",
url="http://dx.doi.org/"
}