Content Provider
University of Wisconsin, Milwaukee: UWM Libraries Digital Collections
1,151
PANGAEA - Data Publisher for Earth & Environmental Science
607
Frontiers: Figshare
575
DataCite Metadata Store (German National Library of Science and Technology)
434
NASA Technical Reports Server (NTRS)
426
NOAA NCEI Environmental Data Archive (via DataONE)
387
Ohio State University (OSU): Knowledge Bank
353
Biodiversity Heritage Library (BHL)
307
Unknown
264
National Library of Australia: Digital Collections
261
University of Calgary Journal Hosting
187
David Rumsey Historical Map Collection (Cartography Associates)
140
Directory of Open Access Journals: DOAJ Articles
113
Harvard University: Harvard Collections
111
Gallica - bibliothèque numérique de la Bibliothèque nationale de France (BnF)
108
Memorial University of Newfoundland: Digital Archives Initiative (DAI)
101
University of North Texas: UNT Digital Library
85
University of Washington, Seattle: Digital Collections
83
Washington State University: WSU Libraries Digital Collections
83
Project Gutenberg (PG)
69
Texas Tech University: TTU DSpace Repository
67
The Online Books Page (Penn Libraries, University of Pennsylvania)
66
Research Data Australia (Australian National Data Service - ANDS)
65
APS Digital Library (American Philosophical Society)
61
Hathi Trust Digital Library
50
AU Digital Research Archive (American University)
47
Defense Technical Information Center: DTIC Technical Reports database
40
UNESDOC - UNESCO Digital Library
40
University of Nevada, Reno: University Digital Conservancy
39
SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy)
38
Zenodo
37
KovsieScholar Repository (University of the Free State - UFS UV)
33
Smithsonian Institution: Figshare
33
USGS Science Data Catalog (via DataONE)
33
Earth-Prints (Istituto Nazionale di Geofisica e Vulcanologia)
31
New York Heritage Digital Collections
31
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe)
29
The Library of Congress: American Memory
29
University of Miami: Digital Collections
28
University of Michigan: Digital Collections
28
eCite UTAS (University of Tasmania)
28
The Portal to Texas History (University of North Texas)
25
Digital Repository of Scientific Institutes (RCIN)
24
Villanova University Falvey Memorial Library: Villanova Digital Library
24
University of Florida: Digital Library Center
22
University of Tasmania: UTas ePrints
21
MDPI Open Access Publishing
20
Bavarian Digital Repository (BDR - Bayerische Staatsbibliothek Munich, BSB)
19
CyberLeninka (Scientific Electronic Library)
19
Université de Nantes: HAL-UNIV-NANTES
19
more ...