@article{ref1,
title="Fentanyl in the US heroin supply: a rapidly changing risk environment",
journal="International journal on drug policy",
year="2017",
author="Ciccarone, Daniel",
volume="46",
number="",
pages="107-111",
abstract="<p>[Abstract unavailable]</p> <p>Language: en</p>",
language="en",
issn="0955-3959",
doi="10.1016/j.drugpo.2017.06.010",
url="http://dx.doi.org/10.1016/j.drugpo.2017.06.010"
}