@article{ref1,
title="A descriptive model for determining optimal human performance in systems. Volume IV. Final summary report. NASA CR-879",
journal="NASA contractor report. NASA CR.",
year="1967",
author="",
volume="ePub",
number="ePub",
pages="1-47",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0565-7059",
doi="",
url="http://dx.doi.org/"
}