The German National Library of Medicine (German: Deutsche Zentralbibliothek für Medizin), abbreviated ZB MED, is the national library of the Federal Republic of Germany for medicine, health sciences, nutrition, agriculture and the environment. It has two locations: Cologne and Bonn. The library is jointly financed by the Federal Ministry of Health and the 16 States of Germany. It is operated under the auspices of the German state of North Rhine-Westphalia.
More information on the Wikipedia page 
The website, in German, is