Content Provider
DataCite Metadata Store (German National Library of Science and Technology)
7,161
University of Washington, Seattle: Digital Collections
4,169
Open Parks Network
2,191
Zenodo
2,158
University of Michigan: Digital Collections
1,449
Unknown
657
Washington State University: WSU Libraries Digital Collections
445
Directory of Open Access Journals: DOAJ Articles
373
University of Calgary Journal Hosting
347
Arctic Data Center (via DataONE)
331
Canadian Science Publishing (via Crossref)
309
The Seattle Public Library Special Collections Online
286
Knowledge Network for Biocomplexity (via DataONE)
224
University of Alaska: ScholarWorks@UA
214
USGS Science Data Catalog (via DataONE)
209
University of Lethbridge Digitized Collections
204
Cambridge University Press
197
Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center)
185
Wiley Online Library
184
Digitized @ Henry Madden Library (FresnoState)
160
Hathi Trust Digital Library
157
University of British Columbia: cIRcle - UBC's Information Repository
152
Arca (BC's Digital Treasures)
151
Wiley Online Library (via Crossref)
142
Canadian Science Publishing
131
Biodiversity Heritage Library (BHL)
129
Arctic Institute of North America (via Crossref)
119
PubMed Central (PMC)
119
PANGAEA - Data Publisher for Earth & Environmental Science
117
Theses Canada/Thèses Canada (Library and Archives Canada)
109
Dryad Digital Repository (Duke University)
92
ScienceDirect (Elsevier - via Crossref)
91
The Library of Congress: American Memory
89
Borealis
82
David Rumsey Historical Map Collection (Cartography Associates)
80
Springer Nature (via Crossref)
80
Defense Technical Information Center: DTIC Technical Reports database
75
RePEc (Research Papers in Economics)
70
Informa (via Crossref)
69
Copernicus Publications: E-Journals
68
Oxford University Press (via Crossref)
57
University of Toronto Press (U Toronto Press - via Crossref)
57
University of the Pacific, McGeorge School of Law: Scholarly Commons
56
University of the Pacific: Scholarly Commons
56
Niedersächsisches Online-Archiv NOA
55
University of Toronto: Research Repository T-Space
54
University of Florida: Digital Library Center
53
uO Research (University of Ottawa - uOttawa)
53
Cambridge University Press (via Crossref)
52
JSTOR (via Crossref)
48
more ...