Content Provider
University of Washington, Seattle: Digital Collections
4,169
DataCite
4,063
DataCite Metadata Store (German National Library of Science and Technology)
3,512
Zenodo
2,257
Open Parks Network
2,191
University of Michigan: Digital Collections
1,449
Unknown
658
Washington State University: WSU Libraries Digital Collections
445
Directory of Open Access Journals: DOAJ Articles
396
University of Calgary Journal Hosting
348
Arctic Data Center (via DataONE)
331
Wiley Online Library
308
The Seattle Public Library Special Collections Online
286
Canadian Science Publishing
248
Knowledge Network for Biocomplexity (via DataONE)
224
University of Alaska: ScholarWorks@UA
224
USGS Science Data Catalog (via DataONE)
209
Cambridge University Press
207
University of Lethbridge Digitized Collections
204
Hathi Trust Digital Library
201
Canadian Science Publishing (via Crossref)
196
Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center)
185
Digitized @ Henry Madden Library (FresnoState)
160
University of British Columbia: cIRcle - UBC's Information Repository
152
Arca (BC's Digital Treasures)
151
Arctic Institute of North America
145
Biodiversity Heritage Library (BHL)
138
PANGAEA - Data Publisher for Earth & Environmental Science
130
PubMed Central (PMC)
127
Theses Canada/Thèses Canada (Library and Archives Canada)
109
Dryad Digital Repository (Duke University)
92
The Library of Congress: American Memory
89
Borealis
82
David Rumsey Historical Map Collection (Cartography Associates)
81
Springer Nature (via Crossref)
80
Defense Technical Information Center: DTIC Technical Reports database
75
ScienceDirect (Elsevier - via Crossref)
75
Copernicus Publications: E-Journals
73
RePEc (Research Papers in Economics)
70
VIURRSpace (Royal Roads University and Vancouver Island University)
69
University of the Pacific, McGeorge School of Law: Scholarly Commons
56
University of the Pacific: Scholarly Commons
56
Informa
55
Niedersächsisches Online-Archiv NOA
55
University of Toronto Press (U Toronto Press - via Crossref)
55
University of Toronto: Research Repository T-Space
54
University of Florida: Digital Library Center
53
uO Research (University of Ottawa - uOttawa)
53
WikiBooks - Open-content textbooks
49
PRISM - University of Calgary Digital Repository
48
more ...