@article{ref1,
title="Head injuries in athletics",
journal="Journal of sports medicine",
year="1974",
author="Blazina, M. E. and Carlson, G. J. and Drake, E. C.",
volume="2",
number="1",
pages="51-56",
abstract="Abstract unavailable.",
language="",
issn="0090-4201",
doi="",
url="http://dx.doi.org/"
}