@article{ref1,
title="Zero Effects of Drug Prevention Programs: Issues and Solutions",
journal="Evaluation review",
year="1998",
author="Brown, Joel H. and Kreft, Ita G. G.",
volume="22",
number="1",
pages="3-14",
abstract="<p>[Abstract unavailable]</p>",
language="",
issn="0193-841X",
doi="",
url="http://dx.doi.org/"
}