@article{ref1,
title="The importance of a simplified classification of motion in sports in relation to performance",
journal="Orthopedic clinics of North America",
year="1977",
author="Nicholas, J. A. and Grossman, R. B. and Hershman, E. B.",
volume="8",
number="3",
pages="499-532",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0030-5898",
doi="",
url="http://dx.doi.org/"
}