Content Provider
DataCite Metadata Store (German National Library of Science and Technology)
3,604
David Rumsey Historical Map Collection (Cartography Associates)
515
NOAA NCEI Environmental Data Archive (via DataONE)
515
Unknown
35
Biodiversity Heritage Library (BHL)
21
LeibnizOpen (The Leibniz Association)
19
Directory of Open Access Journals: DOAJ Articles
18
Zenodo
16
Institute of Earth Environment: IEECAS OpenIR (Chinese Academy of Sciences)
14
PANGAEA - Data Publisher for Earth & Environmental Science
14
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe)
13
PubMed Central (PMC)
13
Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer)
11
Université de Nantes: HAL-UNIV-NANTES
11
Copernicus Publications: E-Journals
9
The Portal to Texas History (University of North Texas)
9
Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center)
8
HAL-CEA (Commissariat à l'énergie atomique et aux énergies alternatives)
8
North Dakota State University (NDSU): Digital Horizons
8
Wiley Online Library
8
Digital Commons University of South Florida (USF)
7
Natural Environment Research Council: NERC Open Research Archive
7
University of South Florida St. Petersburg: Digital USFSP
7
Niedersächsisches Online-Archiv NOA
6
University of Southampton: e-Prints Soton
6
University of the Pacific, McGeorge School of Law: Scholarly Commons
6
University of the Pacific: Scholarly Commons
6
Cambridge University Press
5
USGS Science Data Catalog (via DataONE)
5
University of Calgary Journal Hosting
5
Vrije Universiteit Amsterdam (VU): Research Portal
5
Arctic Data Center (via DataONE)
3
Australian National University: ANU Digital Collections
3
Bellevue University: Digital Archive Collection
3
DR-NTU (Digital Repository at Nanyang Technological University, Singapore)
3
Defense Technical Information Center: DTIC Technical Reports database
3
GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam)
3
Indian Academy of Sciences: Publication of Fellows
3
Max Planck Society: MPG.PuRe
3
National Institute of Oceanography, India: Digital Repository Service (DRS@nio)
3
The University of Queensland: UQ eSpace
3
University of Groningen research database
3
AAAS Resource Center (American Association for the Advancement of Science)
2
Aarhus University: Research
2
Apollo - University of Cambridge Repository
2
BORIS (Bern Open Repository and Information System, University of Bern)
2
Brigham Young University (BYU): Digital Collections
2
Collège de France: HAL
2
DSpace@IIT Bombay (Indian Institute of Technology)
2
Digital.CSIC (Spanish National Research Council)
2
more ...