Content Provider
LeibnizOpen (The Leibniz Association)
18
Copernicus Publications: E-Journals
2
Unknown
2
DataCite Metadata Store (German National Library of Science and Technology)
1
Directory of Open Access Journals: DOAJ Articles
1
ETH ZĂĽrich Research Collection
1
Niedersächsisches Online-Archiv NOA
1
SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy)
1