@article{ref1,
title="Hazards in the building of tunnel and subway sites with propulsion machines as demonstrated at the Alb tunnel construction",
journal="Zentralblatt fur Arbeitsmedizin und Arbeitsschutz",
year="1971",
author="Arnold, K.",
volume="21",
number="9",
pages="298-302",
abstract="<p>[Abstract unavailable]</p><p>Language: de</p>",
language="de",
issn="0044-4049",
doi="",
url="http://dx.doi.org/"
}