@article{ref1,
title="Recreational activity clustering among adolescents",
journal="Research quarterly for exercise and sport",
year="1981",
author="Crompton, J. L. and Vedlitz, A. and Lamb, C. W.",
volume="52",
number="4",
pages="449-457",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0270-1367",
doi="",
url="http://dx.doi.org/"
}