Content Provider
DataCite Metadata Store (German National Library of Science and Technology)
136
University of Nebraska-Lincoln: DigitalCommons@UNL
124
OhioLINK: Ohio Digital Resource Commons (DRC)
65
University of Illinois at Urbana-Champaign: IDEALS (Illinois Digital Environment for Access to Learning and Scholarship)
63
Unknown
61
The University of Utah: J. Willard Marriott Digital Library
53
Utah State University: DigitalCommons@USU
43
JSTOR (via Crossref)
41
SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy)
40
Directory of Open Access Journals: DOAJ Articles
39
Wiley Online Library (via Crossref)
35
Oxford University Press (via Crossref)
34
University of California: eScholarship
31
Biodiversity Heritage Library (BHL)
30
University of North Texas: UNT Digital Library
30
Zenodo
28
Claremont Colleges Digital Library (CCDL)
24
Oregon Digital (University of Oregon/Oregon State University)
24
PubMed Central (PMC)
22
Iowa State University Library Digital Collections
20
BioOne Online Journals
16
Hathi Trust Digital Library
15
RUcore - Rutgers University Community Repository
15
North Dakota State University (NDSU): Digital Horizons
14
ScholarsArchive@OSU (Oregon State University)
14
Wiley Online Library
14
Memorial University of Newfoundland: Digital Archives Initiative (DAI)
13
South Dakota State University (SDSU): Open PRAIRIE (Public Research Access Institutional Repository and Information Exchange)
11
Springer Nature (via Crossref)
11
Open Parks Network
10
University of Calgary Journal Hosting
10
University of Lethbridge Digitized Collections
10
University of Minnesota Digital Conservancy
10
Canadian Science Publishing (via Crossref)
9
JSTOR
9
Montana State University (MSU): ScholarWorks
9
Oregon Institue of Technology (OIT): Digital Collections
9
Digital Repository @ Iowa State University
8
Research Institute Nature and Forest: Research outputs
8
University of Michigan: Deep Blue
8
University of Michigan: Digital Collections
8
University of Washington, Seattle: Digital Collections
8
HighWire Press (Stanford University)
7
Lincoln University (New Zealand): Lincoln U Research Archive
7
Oxford University Press
7
ScienceDirect (Elsevier - via Crossref)
7
South Carolina State Library Digital Collections
7
Theses Canada/Thèses Canada (Library and Archives Canada)
7
WikiBooks - Open-content textbooks
7
Dryad Digital Repository (Duke University)
6
more ...