@article{ref1,
title="Medical factors in U.S. general aviation accidents. AM 69-2",
journal="AM reports",
year="1969",
author="Siegel, P. V. and Mohler, S. R.",
volume="",
number="",
pages="1-6",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="1545-1518",
doi="",
url="http://dx.doi.org/"
}