@article{ref1,
title="The use of bicycle helmets should not be mandatory",
journal="CMAJ : Canadian Medical Association journal",
year="1993",
author="De Marco, TJ",
volume="149",
number="3",
pages="342-344",
abstract="Abstract unavailable.",
language="",
issn="0820-3946",
doi="",
url="http://dx.doi.org/"
}