@article{ref1,
title="The use of cannabis. Report of a WHO scientific group",
journal="World Health Organization technical report series",
year="1971",
author="",
volume="478",
number="",
pages="1-47",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0512-3054",
doi="",
url="http://dx.doi.org/"
}