@article{ref1,
title="Pedestrian Flow and Level of Service",
journal="Journal of transportation engineering",
year="1983",
author="Polus, Abishai and Schofer, Joseph L. and Ushpiz, A",
volume="109",
number="1",
pages="46-56",
abstract="[Abstract unavailable]  <p>Language: en</p>",
language="en",
issn="0733-947X",
doi="",
url="http://dx.doi.org/"
}