@article{ref1,
title="The effect of sleep deprivation on mental performance",
journal="Activitas nervosa superior",
year="1967",
author="Cepelák, J. and Vlasáková, J. and Vojtĕchovský, Miloš",
volume="9",
number="3",
pages="298-299",
abstract="<p>[Abstract unavailable]</p> <p>Language: cs</p>",
language="cs",
issn="0001-7604",
doi="",
url="http://dx.doi.org/"
}