@article{ref1,
title="Depth of penetration of solar protons into the atmosphere and related radiation exposure in supersonic transport",
journal="Aerospace medicine",
year="1963",
author="Schaefer, H. J.",
volume="34",
number="",
pages="1-4",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0001-9402",
doi="",
url="http://dx.doi.org/"
}