@article{ref1,
title="The nighttime legibility of highway signs as a function of their luminance characteristics",
journal="Human factors",
year="1979",
author="Bernstein, A. and Olson, Paul L.",
volume="21",
number="2",
pages="145-160",
abstract="Abstract unavailable.",
language="",
issn="0018-7208",
doi="",
url="http://dx.doi.org/"
}