@article{ref1,
title="Explaining long term trends in violent crime",
journal="Crime, histoire et sociétés",
year="2001",
author="Helmut, T.",
volume="5",
number="2",
pages="69-86",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="1422-0857",
doi="",
url="http://dx.doi.org/"
}