@article{ref1,
title="Relation of preexisting degeneration to accident occurrence",
journal="Zeitschrift fur Orthopadie und Ihre Grenzgebiete",
year="1972",
author="Heipertz, W.",
volume="110",
number="6",
pages="770-773",
abstract="<p>[Abstract unavailable]</p><p>Language: de</p>",
language="de",
issn="0044-3220",
doi="",
url="http://dx.doi.org/"
}