@article{ref1,
title="Psychological aspects of extended manned space flight. Techn docum rep amrl-tdr-63-81",
journal="Aerospace medical research laboratories technical reports",
year="1963",
author="Christensen, J. M.",
volume="",
number="",
pages="1-29",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0192-317X",
doi="",
url="http://dx.doi.org/"
}