@article{ref1,
title="Visual standards for driving and occupations",
journal="Practitioner",
year="1990",
author="Mars, S. and Keightley, S.",
volume="234",
number="1481",
pages="34-35",
abstract="Abstract unavailable.",
language="",
issn="0032-6518",
doi="",
url="http://dx.doi.org/"
}