@article{ref1,
title="Navigation, guidance, and control problems of spacecraft",
journal="Annals of the New York Academy of Sciences",
year="1965",
author="Hoag, D. G.",
volume="134",
number="1",
pages="459-474",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0077-8923",
doi="",
url="http://dx.doi.org/"
}