@article{ref1,
title="The Relationship Between Cities and Traffic",
journal="Zeitschrift des Vereines Deutscher Ingenieure",
year="1921",
author="Blum, ",
volume="65",
number="",
pages="345-347",
abstract="<p>[Abstract unavailable]</p>",
language="",
issn="0341-7255",
doi="",
url="http://dx.doi.org/"
}