@article{ref1,
title="The efficiency of two dimensional traffic markers in referring commmands",
journal="Human factors",
year="1964",
author="Nelson, Thomas M.",
volume="36",
number="",
pages="359-364",
abstract="<p>[Abstract unavailable]</p> <p>Language: en</p>",
language="en",
issn="0018-7208",
doi="",
url="http://dx.doi.org/"
}