Content Provider
DataCite Metadata Store (German National Library of Science and Technology)
1,740
Unknown
16
Directory of Open Access Journals: DOAJ Articles
15
NASA Technical Reports Server (NTRS)
14
Australian National University: ANU Digital Collections
10
Springer Nature (via Crossref)
9
Copernicus Publications: E-Journals
8
Opin vísindi (Iceland)
8
Niedersächsisches Online-Archiv NOA
7
ScienceDirect (Elsevier)
7
Cambridge University Press
6
PubMed Central (PMC)
6
SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy)
6
Skemman (Iceland)
6
Zenodo
6
IRIS Università degli Studi di Napoli Federico II
5
University of North Texas: UNT Digital Library
5
GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam)
4
UNESDOC - UNESCO Digital Library
3
University of Bergen: Bergen Open Research Archive (BORA-UiB)
3
University of California: eScholarship
3
University of Copenhagen: Research
3
Biodiversity Heritage Library (BHL)
2
Caltech Authors (California Institute of Technology)
2
Defense Technical Information Center: DTIC Technical Reports database
2
Informa (via Crossref)
2
Institut national des sciences de l'Univers: HAL-INSU
2
Lund University Publications (LUP)
2
MDPI Open Access Publishing
2
Maynooth University ePrints and eTheses Archive (National University of Ireland)
2
PANGAEA - Data Publisher for Earth & Environmental Science
2
ScienceDirect (Elsevier - via Crossref)
2
Technical University of Denmark: DTU Orbit
2
University of Michigan: Digital Collections
2
eCite UTAS (University of Tasmania)
2
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe)
1
Brill
1
Cairn (E-Journals)
1
DigiZeitschriften: The German digital journal archive (Göttingen University Library)
1
Flanders Marine Institute (VLIZ): Open Marine Archive (OMA)
1
Frontiers (Publisher)
1
Frontiers: Figshare
1
GEO-LEOe-docs (FID GEO)
1
GFZ Data Services (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam)
1
HAL Clermont Auvergne (Université Blaise Pascal Clermont-Ferrand/Université d'Auvergne)
1
HELDA – University of Helsinki Open Repository
1
Hathi Trust Digital Library
1
IRIS Università degli Studi di Bologna (CRIS - Current Research Information System)
1
IRUA - Institutional Repository van de Universiteit Antwerpen
1
Jagiellonian University Repository
1
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