@article{ref1,
title="Early warning signs",
journal="Deutsches Ärzteblatt International",
year="2009",
author="Stutzer, Harald",
volume="106",
number="27",
pages="468; author reply 468-468; author reply 468",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="1866-0452",
doi="10.3238/arztebl.2009.0468a",
url="http://dx.doi.org/10.3238/arztebl.2009.0468a"
}