@article{ref1,
title="Visual aging and the visibility of highway signs",
journal="Experimental aging research",
year="1991",
author="Kline, D. W.",
volume="17",
number="2",
pages="80-81",
abstract="<p>[Abstract unavailable]</p> <p>Language: en</p>",
language="en",
issn="0361-073X",
doi="",
url="http://dx.doi.org/"
}