@article{ref1,
title="National parks: traffic jams turn attention to roads",
journal="Science",
year="1968",
author="Carter, L. J.",
volume="161",
number="3843",
pages="770-772",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0036-8075",
doi="10.1126/science.161.3843.770",
url="http://dx.doi.org/10.1126/science.161.3843.770"
}