Content Provider
DataCite Metadata Store (German National Library of Science and Technology)
21,314
PANGAEA - Data Publisher for Earth & Environmental Science
7,452
Unknown
4,500
Directory of Open Access Journals: DOAJ Articles
3,617
University of Copenhagen: Research
3,151
University of Michigan: Digital Collections
2,750
Arctic Data Center (via DataONE)
2,708
Aarhus University: Research
2,315
Zenodo
2,046
ScienceDirect (Elsevier - via Crossref)
1,838
Cambridge University Press
1,624
Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center)
1,470
Copernicus Publications: E-Journals
1,463
Springer Nature (via Crossref)
1,425
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe)
1,361
Technical University of Denmark: DTU Orbit
1,333
LeibnizOpen (The Leibniz Association)
1,238
PubMed Central (PMC)
1,029
Wiley Online Library (via Crossref)
1,018
Niedersächsisches Online-Archiv NOA
928
Université de Nantes: HAL-UNIV-NANTES
914
Institut national des sciences de l'Univers: HAL-INSU
912
David Rumsey Historical Map Collection (Cartography Associates)
896
NOAA NCEI Environmental Data Archive (via DataONE)
896
Defense Technical Information Center: DTIC Technical Reports database
867
Informa (via Crossref)
807
University of Wisconsin, Milwaukee: UWM Libraries Digital Collections
738
Wiley Online Library
731
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel)
622
Natural Environment Research Council: NERC Open Research Archive
570
University of California: eScholarship
553
Biodiversity Heritage Library (BHL)
519
ScienceDirect (Elsevier)
489
NASA Technical Reports Server (NTRS)
447
University of Southern Denmark Research Portal
442
Apollo - University of Cambridge Repository
441
University of Calgary Journal Hosting
439
Utrecht University Repository
439
Digital.CSIC (Spanish National Research Council)
427
HighWire Press (Stanford University)
409
GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam)
393
JSTOR (via Crossref)
371
Aalborg University's Research Portal
348
Université de Versailles Saint-Quentin-en-Yvelines: HAL-UVSQ
348
Aarhus University: OJS at The State and University Library
347
Tidsskrift.dk (The Royal Library, Denmark)
347
Lund University Publications (LUP)
338
HAL-CEA (Commissariat à l'énergie atomique et aux énergies alternatives)
328
BORIS (Bern Open Repository and Information System, University of Bern)
322
Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer)
312
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