@article{ref1,
title="Survey of national emergency telephone number systems; operational characteristics of 911 systems",
journal="Hospital progress",
year="1975",
author="Prybil, L. D.",
volume="56",
number="5",
pages="64-69",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0018-5817",
doi="",
url="http://dx.doi.org/"
}