@article{ref1,
title="Evaluating Controller Communication Time As a Measure of Workload",
journal="International journal of aviation psychology",
year="1997",
author="Porterfield, Douglas H.",
volume="7",
number="2",
pages="171-182",
abstract="[Abstract unavailable]  <p>Language: en</p>",
language="en",
issn="1050-8414",
doi="10.1207/s15327108ijap0702_5",
url="http://dx.doi.org/10.1207/s15327108ijap0702_5"
}