Content Provider
University of Michigan: Digital Collections
4,494
Memorial University of Newfoundland: Digital Archives Initiative (DAI)
3,625
DataCite Metadata Store (German National Library of Science and Technology)
3,547
University of Wisconsin, Milwaukee: UWM Libraries Digital Collections
1,383
Memorial University of Newfoundland: Research Repository
632
Unknown
539
Directory of Open Access Journals: DOAJ Articles
331
PubMed Central (PMC)
228
Borealis
203
Hathi Trust Digital Library
200
Wiley Online Library
159
David Rumsey Historical Map Collection (Cartography Associates)
147
Biodiversity Heritage Library (BHL)
139
RePEc (Research Papers in Economics)
112
Canadian Science Publishing (via Crossref)
110
WikiBooks - Open-content textbooks
103
University of Lethbridge Digitized Collections
96
Springer Nature (via Crossref)
82
Cambridge University Press
72
University of New Brunswick: Centre for Digital Scholarship Journals
71
ScienceDirect (Elsevier - via Crossref)
69
HighWire Press (Stanford University)
68
Érudit.org (Université Montréal)
64
Dryad Digital Repository (Duke University)
59
MDPI Open Access Publishing
55
University of Toronto: Research Repository T-Space
55
Zenodo
54
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe)
53
Cambridge University Press (via Crossref)
49
Theses Canada/Thèses Canada (Library and Archives Canada)
48
Dalhousie University: DalSpace Institutional Repository
46
Canadian Science Publishing
45
The Portal to Texas History (University of North Texas)
43
Arca (BC's Digital Treasures)
38
York University Digital Library
38
Biological and Chemical Oceanography Data Management Office (BCO-DMO) (via DataONE)
37
University of Washington, Seattle: Digital Collections
37
National Research Council Canada: NRC Publications Archive
36
Apollo - University of Cambridge Repository
35
Saint Mary's University, Halifax: Institutional Repository
35
University of Calgary Journal Hosting
34
Oxford University Press (via Crossref)
33
BioOne Online Journals
31
DataCite
31
Defense Technical Information Center: DTIC Technical Reports database
31
Gallica - bibliothèque numérique de la Bibliothèque nationale de France (BnF)
30
BioMed Central
27
Georgetown University: DigitalGeorgetown
27
ScienceDirect (Elsevier)
27
Queen's University, Ontario: QSpace
26
more ...