Content Provider
DataCite Metadata Store (German National Library of Science and Technology)
60
Frankfurt/Main University Library: Digitale Sammlungen
4
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel)
3
Springer Nature (via Crossref)
2
University of Freiburg: FreiDok
2
University of Wisconsin, Milwaukee: UWM Libraries Digital Collections
2
ediss.sub.hamburg (Staats- und Universitätsbibliothek Hamburg, Carl von Ossietzky)
2
Directory of Open Access Journals: DOAJ Articles
1
Unknown
1