@article{ref1,
title="Aviation accidents caused by human failures",
journal="Hefte zur Unfallheilkunde",
year="1960",
author="Ruff, S.",
volume="62",
number="",
pages="53-62",
abstract="<p>[Abstract unavailable]</p><p>Language: de</p>",
language="de",
issn="0085-1469",
doi="",
url="http://dx.doi.org/"
}