@article{ref1,
title="Hip fractures are an increasingly important public health problem",
journal="Clinical orthopaedics and related research",
year="1998",
author="Koval, K. J. and Zuckerman, J. D.",
volume="",
number="348",
pages="2-2",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0009-921X",
doi="",
url="http://dx.doi.org/"
}