@article{ref1,
title="Emergency safety lighting from the Ruhstrat brothers, Goettingen",
journal="Physikalische Zeitschrift",
year="1900",
author="",
volume="2",
number="",
pages="26-28",
abstract="<p>[Abstract unavailable]</p><p>Language: de</p>",
language="",
issn="",
doi="",
url="http://dx.doi.org/"
}