@article{ref1,
title="Medical factors in U. S. general aviation accidents",
journal="Aerospace medicine",
year="1969",
author="Siegel, P. V. and Mohler, S. R.",
volume="40",
number="2",
pages="180-184",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0001-9402",
doi="",
url="http://dx.doi.org/"
}