@article{ref1,
title="Threshold values and the psychophysical function in brightness vision",
journal="Vision research",
year="1968",
author="Ekman, G. and Gustafsson, U.",
volume="8",
number="6",
pages="747-758",
abstract="<p>[Abstract unavailable]</p> <p>Language: en</p>",
language="en",
issn="0042-6989",
doi="",
url="http://dx.doi.org/"
}