- Correspondence to Dr Nicholas Henschke, Institute of Public Health, University of Heidelberg, Im Neuenheimer Feld 324, Heidelberg 69120, Germany;
- Accepted January 17, 2014
- First published February 18, 2014.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.