Content Provider
DataCite Metadata Store (German National Library of Science and Technology)
22,376
PANGAEA - Data Publisher for Earth & Environmental Science
7,494
Unknown
4,563
Directory of Open Access Journals: DOAJ Articles
3,634
University of Copenhagen: Research
3,248
University of Michigan: Digital Collections
2,752
Arctic Data Center (via DataONE)
2,708
Aarhus University: Research
2,559
Zenodo
2,088
ScienceDirect (Elsevier - via Crossref)
1,838
Cambridge University Press
1,635
Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center)
1,476
Copernicus Publications: E-Journals
1,470
Springer Nature (via Crossref)
1,425
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe)
1,378
Technical University of Denmark: DTU Orbit
1,349
LeibnizOpen (The Leibniz Association)
1,327
PubMed Central (PMC)
1,038
Wiley Online Library
991
Institut national des sciences de l'Univers: HAL-INSU
964
Niedersächsisches Online-Archiv NOA
964
Université de Nantes: HAL-UNIV-NANTES
915
David Rumsey Historical Map Collection (Cartography Associates)
897
NOAA NCEI Environmental Data Archive (via DataONE)
896
Defense Technical Information Center: DTIC Technical Reports database
867
Wiley Online Library (via Crossref)
850
Informa (via Crossref)
751
University of Wisconsin, Milwaukee: UWM Libraries Digital Collections
738
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel)
624
Natural Environment Research Council: NERC Open Research Archive
571
University of California: eScholarship
570
Biodiversity Heritage Library (BHL)
521
ScienceDirect (Elsevier)
489
University of Southern Denmark Research Portal
464
NASA Technical Reports Server (NTRS)
447
Apollo - University of Cambridge Repository
444
Utrecht University Repository
443
University of Calgary Journal Hosting
439
Digital.CSIC (Spanish National Research Council)
428
HighWire Press (Stanford University)
409
GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam)
400
Oxford University Press (via Crossref)
383
JSTOR (via Crossref)
377
Université de Versailles Saint-Quentin-en-Yvelines: HAL-UVSQ
369
Aalborg University's Research Portal
356
Aarhus University: OJS at The State and University Library
348
Tidsskrift.dk (The Royal Library, Denmark)
348
University of Liège: ORBi (Open Repository and Bibliography)
346
Lund University Publications (LUP)
341
HAL-CEA (Commissariat à l'énergie atomique et aux énergies alternatives)
340
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