@article{ref1,
title="Multiple authorship: trends over 50 years in the Journal of Studies on Alcohol",
journal="Journal of studies on alcohol",
year="1996",
author="Howard, M. O. and Walker, R. Dale",
volume="57",
number="1",
pages="105-106",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0096-882X",
doi="",
url="http://dx.doi.org/"
}