@article{ref1,
title="Armed America: demands on the EMS system",
journal="Emergency medical services",
year="1990",
author="Callahan, B. M.",
volume="19",
number="11",
pages="24-26",
abstract="<p>[Abstract unavailable]</p> <p>Language: en</p>",
language="en",
issn="0094-6575",
doi="",
url="http://dx.doi.org/"
}