@article{ref1,
title="Experiments on visual acuity and the visibility of markings on the ground in long-duration earth-orbital space flight. NASA CR-1134",
journal="NASA contractor report. NASA CR.",
year="1968",
author="Duntley, S. Q. and Austin, R. W. and Harris, J. L. and Taylor, J. H.",
volume="ePub",
number="ePub",
pages="1-227",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0565-7059",
doi="",
url="http://dx.doi.org/"
}