@article{ref1,
title="Medical and environmental problems in agricultural aviation",
journal="Aerospace medicine",
year="1963",
author="Billings, C. E.",
volume="34",
number="",
pages="406-408",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0001-9402",
doi="",
url="http://dx.doi.org/"
}