@article{ref1,
title="Instructional system approach to flight crew training",
journal="Human factors",
year="1966",
author="Wallis, K. B. and Ewart, W. L. and Kaufman, R. A.",
volume="8",
number="2",
pages="173-178",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0018-7208",
doi="",
url="http://dx.doi.org/"
}