@article{ref1,
title="Prison Commitments, Crime and Unemployment: A Theoretical and Empirical Specification for the U.S., 1933-85",
journal="Journal of quantitative criminology",
year="1991",
author="Chappell, Charles L. and Sykes, Gresham",
volume="7",
number="",
pages="155-200",
abstract="<p>[Abstract unavailable]</p>",
language="",
issn="0748-4518",
doi="",
url="http://dx.doi.org/"
}