Content Provider
DataCite Metadata Store (German National Library of Science and Technology)
50,500
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
PubMed Central (PMC)
1,492
University of Washington, Seattle: Digital Collections
1,471
Canadian Science Publishing (via Crossref)
1,377
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe)
1,020
Wiley Online Library (via Crossref)
969
University of Calgary Journal Hosting
959
Arctic Data Center (via DataONE)
954
PANGAEA - Data Publisher for Earth & Environmental Science
946
Cambridge University Press
914
ScienceDirect (Elsevier - via Crossref)
896
SFU Digitized Collections (Simon Fraser University)
892
Wiley Online Library
870
Memorial University of Newfoundland: Research Repository
866
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
Defense Technical Information Center: DTIC Technical Reports database
645
Informa (via Crossref)
641
Université de Nantes: HAL-UNIV-NANTES
599
David Rumsey Historical Map Collection (Cartography Associates)
576
Biodiversity Heritage Library (BHL)
556
Érudit.org (Université Montréal)
534
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
Canadian Science Publishing
359
National Research Council Canada: NRC Publications Archive
357
Niedersächsisches Online-Archiv NOA
351
Dalhousie University: DalSpace Institutional Repository
349
HighWire Press (Stanford University)
344
Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center)
339
LeibnizOpen (The Leibniz Association)
324
Arctic Council Repository
320
more ...