@article{ref1,
title="Current concepts. Concussion in sports",
journal="American journal of sports medicine",
year="1999",
author="Wojtys, E. M. and Hovda, David A. and Landry, Gregory L. and Boland, A. and Lovell, M. and McCrea, M. and Minkoff, J.",
volume="27",
number="5",
pages="676-687",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0363-5465",
doi="",
url="http://dx.doi.org/"
}