@article{ref1,
title="Hazards and injuries in crossing railroad tunnels",
journal="Zdravno Delo",
year="1952",
author="Naidenov, I. S.",
volume="6",
number="2",
pages="45-48",
abstract="<p>[Abstract unavailable]</p><p>Language: un</p>",
language="un",
issn="",
doi="",
url="http://dx.doi.org/"
}