@article{ref1,
title="Work-load and work-time with reference to limits of tolerance in physical work",
journal="Zentralblatt für Arbeitsmedizin, Arbeitsschutz, Prophylaxe und Ergonomie",
year="1981",
author="Ulmer, H. V.",
volume="31",
number="1",
pages="14-16",
abstract="<p>[Abstract unavailable]</p><p>Language: de</p>",
language="de",
issn="0173-3338",
doi="",
url="http://dx.doi.org/"
}