@article{ref1,
title="Sleep disorders in aging and aged persons",
journal="ZFA. Zeitschrift für Allgemeinmedizin",
year="1977",
author="Werner, W.",
volume="53",
number="33",
pages="2078-2084",
abstract="<p>[Abstract unavailable]</p><p>Language: de</p>",
language="de",
issn="1433-6251",
doi="",
url="http://dx.doi.org/"
}