@article{ref1,
title="Helmets for motor-cyclists: are there any medical grounds for exemption?",
journal="Medical journal of Australia",
year="1989",
author="Trinca, Gordon W. and Simpson, D. A.",
volume="150",
number="4",
pages="227-227",
abstract="Abstract unavailable.",
language="",
issn="0025-729X",
doi="",
url="http://dx.doi.org/"
}