@article{ref1,
title="Day-night differences are not always due to circadian control",
journal="Annals of emergency medicine",
year="1992",
author="Hastings, J. W. and Czeisler, Charles A.",
volume="21",
number="10",
pages="1236-1236",
abstract="<p>[Abstract unavailable]</p> <p>Language: en</p>",
language="en",
issn="0196-0644",
doi="",
url="http://dx.doi.org/"
}