@article{ref1,
title="Tackle football in pre-high school children",
journal="Journal of sports medicine and physical fitness",
year="1966",
author="Castellanos, A. Jr and Greer, P.",
volume="6",
number="3",
pages="187-190",
abstract="<p>[Abstract unavailable]  Keywords: American football; </p> <p>Language: en</p>",
language="en",
issn="0022-4707",
doi="",
url="http://dx.doi.org/"
}