@article{ref1,
title="Ergonomic assessment of work time and performance rhythm (II)",
journal="Quintessenz Zahntech",
year="1977",
author="Kimmel, K.",
volume="3",
number="9",
pages="69-72",
abstract="<p>[Abstract unavailable]</p><p>Language: de</p>",
language="de",
issn="0340-4641",
doi="",
url="http://dx.doi.org/"
}