@article{ref1,
title="The influence of 'biorhythm' on accident occurrence and performance",
journal="Ergonomics",
year="1977",
author="Khalil, T. M. and Kurucz, C. N.",
volume="20",
number="4",
pages="389-398",
abstract="<p>[Abstract unavailable]</p> <p>Language: en</p>",
language="en",
issn="0014-0139",
doi="",
url="http://dx.doi.org/"
}