@article{ref1,
title="Sports capacity, sports fitness and inability to participate in school sports in childhood and adolescence",
journal="Arztliche Jugendkunde",
year="1990",
author="Ratzmann, G. W.",
volume="81",
number="4",
pages="299-302",
abstract="<p>[Abstract unavailable]</p><p>Language: de</p>",
language="de",
issn="0001-9518",
doi="",
url="http://dx.doi.org/"
}