@article{ref1,
title="Sensory alternation and performance in a vigilance task",
journal="Human factors",
year="1964",
author="Gruber, A.",
volume="79",
number="",
pages="3-12",
abstract="<p>[Abstract unavailable]</p> <p>Language: en</p>",
language="en",
issn="0018-7208",
doi="",
url="http://dx.doi.org/"
}