@article{ref1,
title="Impact-absorbing qualities of football helmets",
journal="Research quarterly",
year="1965",
author="Kovacic, C. R.",
volume="36",
number="4",
pages="421-426",
abstract="<p>[Abstract unavailable]  Keywords: American football </p> <p>Language: en</p>",
language="en",
issn="0034-5377",
doi="",
url="http://dx.doi.org/"
}