Content Provider
DataCite Metadata Store (German National Library of Science and Technology)
3
Unknown
3
Directory of Open Access Journals: DOAJ Articles
2
German Aerospace Center: elib - DLR electronic library
2
Media SuUB Bremen (Staats- und Universitätsbibliothek Bremen)
2
University of Wisconsin, Milwaukee: UWM Libraries Digital Collections
2
Bavarian Digital Repository (BDR - Bayerische Staatsbibliothek Munich, BSB)
1
MACAU: Open Access Repository of Kiel University
1
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel)
1
UNESDOC - UNESCO Digital Library
1
da|ra - Registration agency for social and economic data
1