@article{ref1,
title="Introduction to railway signalling",
journal="Indian railways",
year="2008",
author="Yadav, Mahesh",
volume="54",
number="4",
pages="13-16",
abstract="<p>[Abstract unavailable]</p>",
language="",
issn="0019-6274",
doi="",
url="http://dx.doi.org/"
}