Content Provider
DataCite Metadata Store (German National Library of Science and Technology)
51,536
University of Michigan: Digital Collections
13,978
Unknown
5,456
Memorial University of Newfoundland: Digital Archives Initiative (DAI)
5,381
Directory of Open Access Journals: DOAJ Articles
3,661
University of Lethbridge Digitized Collections
2,554
Zenodo
2,479
University of Wisconsin, Milwaukee: UWM Libraries Digital Collections
1,612
David Rumsey Historical Map Collection (Cartography Associates)
1,535
Canadian Science Publishing (via Crossref)
1,500
PubMed Central (PMC)
1,492
University of Washington, Seattle: Digital Collections
1,471
Wiley Online Library
1,360
PANGAEA - Data Publisher for Earth & Environmental Science
1,099
Cambridge University Press
1,065
Wiley Online Library (via Crossref)
1,038
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe)
1,020
University of Calgary Journal Hosting
960
Arctic Data Center (via DataONE)
954
ScienceDirect (Elsevier - via Crossref)
896
SFU Digitized Collections (Simon Fraser University)
892
Memorial University of Newfoundland: Research Repository
869
Theses Canada/Thèses Canada (Library and Archives Canada)
837
NOAA NCEI Environmental Data Archive (via DataONE)
818
RePEc (Research Papers in Economics)
786
Springer Nature (via Crossref)
725
Informa (via Crossref)
685
Canadian Science Publishing
650
Defense Technical Information Center: DTIC Technical Reports database
645
Université de Nantes: HAL-UNIV-NANTES
606
Biodiversity Heritage Library (BHL)
558
Érudit.org (Université Montréal)
541
Gallica - bibliothèque numérique de la Bibliothèque nationale de France (BnF)
516
University of British Columbia: cIRcle - UBC's Information Repository
480
WikiBooks - Open-content textbooks
469
Copernicus Publications: E-Journals
458
University of Nebraska-Lincoln: DigitalCommons@UNL
452
University of Toronto: Research Repository T-Space
450
Dryad Digital Repository (Duke University)
440
MDPI Open Access Publishing
438
Borealis
428
North Dakota State University (NDSU): Digital Horizons
416
MIT Libraries Dome
391
National Research Council Canada: NRC Publications Archive
357
Niedersächsisches Online-Archiv NOA
353
Université Laval: CorpusUL
353
Dalhousie University: DalSpace Institutional Repository
349
HighWire Press (Stanford University)
344
Institut national des sciences de l'Univers: HAL-INSU
344
Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center)
340
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