@article{ref1,
title="Engineering of traffic markers to satisfy requirements of perceptual space",
journal="Ergonomics",
year="1972",
author="Nelson, Thomas M. and Ladan, C. J.",
volume="15",
number="5",
pages="527-536",
abstract="<p>[Abstract unavailable]</p> <p>Language: en</p>",
language="en",
issn="0014-0139",
doi="",
url="http://dx.doi.org/"
}