@article{ref1,
title="Watchkeeping performance as a function of certain properties of the viewing situation",
journal="Human factors",
year="1974",
author="Bell, Rebecca A. R. and Symington, L. E. and Bevan, W.",
volume="16",
number="1",
pages="65-69",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0018-7208",
doi="",
url="http://dx.doi.org/"
}