DOI:
10.1055/s-00000011
DMW - Deutsche Medizinische Wochenschrift
LinksClose Window
References
Oxford Centre for Evidence-based Medicine.
Levels of Evidence.
2009.
http://www.cebm.net/oxford-centre-evidence-based-medicine-levels-evidence-march-2009 downloaded 23.02.2015
We do not assume any responsibility for the contents of the web pages of other providers.