@article{ref1,
title="Alcohol use and sexual risk-taking among adolescents: methodological approaches for addressing causal issues",
journal="Progress in clinical and biological research",
year="1990",
author="Cooper, M. L. and Skinner, J. B. and George, W. H.",
volume="325",
number="",
pages="11-19",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0361-7742",
doi="",
url="http://dx.doi.org/"
}