@article{ref1,
title="Urban planning, transportation, and systems analysis",
journal="Proceedings of the National Academy of Sciences of the United States of America",
year="1960",
author="Boelter, L. M. and Branch, M. C.",
volume="46",
number="6",
pages="824-831",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0027-8424",
doi="",
url="http://dx.doi.org/"
}