Content Provider
DataCite Metadata Store (German National Library of Science and Technology)
4,058
David Rumsey Historical Map Collection (Cartography Associates)
1,481
University of Wisconsin, Milwaukee: UWM Libraries Digital Collections
1,383
IEDA: Marine-Geo Digital Library (via DataONE)
1,237
USGS Science Data Catalog (via DataONE)
768
Arctic Data Center (via DataONE)
618
NOAA NCEI Environmental Data Archive (via DataONE)
441
Research Data Australia (Australian National Data Service - ANDS)
322
Unknown
144
University of Washington, Seattle: Digital Collections
101
Cambridge University Press
98
CyberLeninka (Scientific Electronic Library)
96
RePEc (Research Papers in Economics)
88
Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center)
67
IOP Publishing
67
NASA Technical Reports Server (NTRS)
63
Zenodo
62
North Dakota State University (NDSU): Digital Horizons
51
ArXiv.org (Cornell University Library)
48
Frontiers: Figshare
43
German Aerospace Center: elib - DLR electronic library
42
Chalmers University of Technology: Chalmers research
38
Frontiers (Publisher)
36
National Library of Australia: Digital Collections
33
Northern Arizona University (NAU): Special Collections and Archives
31
IEEE Publications (via Crossref)
30
Biological and Chemical Oceanography Data Management Office (BCO-DMO) (via DataONE)
29
Brill
29
Digital.CSIC (Spanish National Research Council)
24
YUNOCA - Yamaguchi University Navigator for Open access Collection and Archives
23
Springer Nature
22
Springer Nature (via Crossref)
22
Dryad Digital Repository (Duke University)
19
IEDA: US Antarctic Program Data Center (via DataONE)
19
Brill (via Crossref)
18
Oxford University Press (via Crossref)
18
SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy)
18
University of New Hampshire: Scholars Repository
17
GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam)
16
Natural Environment Research Council: NERC Open Research Archive
16
OhioLINK: Ohio Digital Resource Commons (DRC)
16
University of Michigan: Deep Blue
16
Data Archiving and Networked Services (DANS): EASY (KNAW - Koninklijke Nederlandse Akademie van Wetenschappen)
15
National Research Council Canada: NRC Publications Archive
15
Queensland University of Technology: QUT ePrints
15
Schulich Scholars (Schulich School of Law, Dalhousie University)
15
University of Nebraska-Lincoln: DigitalCommons@UNL
14
IEEE Publications
13
Naval Postgraduate School: Calhoun
13
World Maritime University (WMU): Maritime Commons
13
more ...