- Correspondence to Daniel Medenwald, Institute of Medical Epidemiology, Biostatistics, and Informatics, Medical Faculty, Martin-Luther-University of Halle-Wittenberg, Magdeburger Str. 8, Halle (Saale) 06112, Germany;
- Received May 14, 2013
- Revised January 7, 2014
- Accepted April 11, 2014
- First published May 8, 2014.
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