@article{ref1,
title="Age comparison of human day-night physiological differences",
journal="Aerospace medicine",
year="1968",
author="Cahn, H. A. and Folk, G. E. and Huston, P. E.",
volume="39",
number="6",
pages="608-610",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0001-9402",
doi="",
url="http://dx.doi.org/"
}