@article{ref1,
title="Cyclists should wear helmets. health benefits of cycling greatly outweigh loss of life years from deaths",
journal="British medical journal: BMJ",
year="1997",
author="Hillman, M.",
volume="314",
number="7073",
pages="70-70",
abstract="Abstract unavailable.",
language="",
issn="0959-8138",
doi="",
url="http://dx.doi.org/"
}