@article{ref1,
title="Changes in the circadian rhythm of performance and mood in healthy young men exposed to prolonged, heavy physical work, sleep deprivation, and caloric deficit",
journal="Aviation, space, and environmental medicine",
year="1979",
author="Bugge, J. F. and Opstad, P. K. and Magnus, P. M.",
volume="50",
number="7",
pages="663-668",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0095-6562",
doi="",
url="http://dx.doi.org/"
}