@article{ref1,
title="A descriptive model for determining optimal human performance in systems. II. A. System development activities concerned with putting man in an aerospace system. NASA CR-877",
journal="NASA contractor report. NASA CR.",
year="1967",
author="",
volume="ePub",
number="ePub",
pages="1-250",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0565-7059",
doi="",
url="http://dx.doi.org/"
}