@article{ref1,
title="Patterns of drug abuse",
journal="International journal of the addictions",
year="1974",
author="Campbell, R. S. and Freeland, J. B.",
volume="9",
number="2",
pages="289-300",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0020-773X",
doi="",
url="http://dx.doi.org/"
}