@article{ref1,
title="Provided with safety shaft-head",
journal="Zentralblatt fur Arbeitsmedizin und Arbeitsschutz",
year="1970",
author="Sterling, W. K.",
volume="20",
number="8",
pages="252-253",
abstract="<p>[Abstract unavailable]</p><p>Language: de</p>",
language="de",
issn="0044-4049",
doi="",
url="http://dx.doi.org/"
}