@article{ref1,
title="Cardiac contusion caused by the use of a jackhammer",
journal="American heart journal",
year="1957",
author="Chapman, M. G. and McEACHEN, J. A.",
volume="54",
number="4",
pages="625-627",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0002-8703",
doi="",
url="http://dx.doi.org/"
}