@article{ref1,
title="Heading in soccer--time for a rethink?",
journal="British journal of general practice",
year="1999",
author="Kernick, D. P.",
volume="49",
number="440",
pages="171-171",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0960-1643",
doi="",
url="http://dx.doi.org/"
}