@article{ref1,
title="Using Knowledge Exploration Tools to Study Airspace Complexity in Air Traffic Control",
journal="International journal of aviation psychology",
year="1994",
author="Mogford, Richard H. and Murphy, Elizabeth D. and Guttman, Jeremy A.",
volume="4",
number="1",
pages="29-45",
abstract="<p>[Abstract unavailable]</p>",
language="",
issn="1050-8414",
doi="10.1207/s15327108ijap0401_2",
url="http://dx.doi.org/10.1207/s15327108ijap0401_2"
}