@article{ref1,
title="A survey of cannabis use in offshore rig workers",
journal="British journal of addiction",
year="1987",
author="Calder, I. M. and Ramsey, J.",
volume="82",
number="2",
pages="159-161",
abstract="<p>[Abstract unavailable]</p> <p>Language: en</p>",
language="en",
issn="0952-0481",
doi="",
url="http://dx.doi.org/"
}