@article{ref1,
title="Protection and warning helmet",
journal="Zentralblatt fur Arbeitsmedizin und Arbeitsschutz",
year="1969",
author="Sterling, W. K.",
volume="19",
number="11",
pages="347-347",
abstract="<p>[Abstract unavailable]</p><p>Language: de</p>",
language="de",
issn="0044-4049",
doi="",
url="http://dx.doi.org/"
}