@article{ref1,
title="A system of vision testing for motor vehicle drivers",
journal="Canadian services medical journal",
year="1956",
author="Nicholls, J. V.",
volume="12",
number="3",
pages="215-26; discussion, 237",
abstract="<p>[Abstract unavailable]</p> <p>Language: en</p>",
language="en",
issn="",
doi="",
url="http://dx.doi.org/"
}