Content Provider
DataCite Metadata Store (German National Library of Science and Technology)
1,331
NOAA NCEI Environmental Data Archive (via DataONE)
95
Zenodo
51
Unknown
47
LeibnizOpen (The Leibniz Association)
39
Missouri State University: Digital Collections
33
Directory of Open Access Journals: DOAJ Articles
19
PubMed Central (PMC)
17
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe)
15
Wiley Online Library
15
North Dakota State University (NDSU): Digital Horizons
14
PANGAEA - Data Publisher for Earth & Environmental Science
14
Washington State University: WSU Libraries Digital Collections
13
The University of Utah: J. Willard Marriott Digital Library
11
Université de Nantes: HAL-UNIV-NANTES
11
HighWire Press (Stanford University)
10
WikiBooks - Open-content textbooks
10
Cambridge University Press
9
RePEc (Research Papers in Economics)
9
David Rumsey Historical Map Collection (Cartography Associates)
8
Defense Technical Information Center: DTIC Technical Reports database
8
Hunter Library Digital Collections (Western Carolina University)
7
Institut national des sciences de l'Univers: HAL-INSU
7
Opin vísindi (Iceland)
7
University of Southampton: e-Prints Soton
7
Magnolia press
6
Skemman (Iceland)
6
Copernicus Publications: E-Journals
5
Dryad Digital Repository (Duke University)
5
Ghent University Academic Bibliography
5
Peking University Institutional Repository (PKU IR)
5
SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy)
5
The University of Queensland: UQ eSpace
5
University of North Texas: UNT Digital Library
5
University of St Andrews: Research Portal
5
Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server)
5
Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center)
4
Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer)
4
Caltech Authors (California Institute of Technology)
4
Flanders Marine Institute (VLIZ): Open Marine Archive (OMA)
4
GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam)
4
Natural Environment Research Council: NERC Open Research Archive
4
Pensoft Publishers
4
Rice University: Digital Scholarship Archive
4
University of Bristol: Bristol Research
4
University of Cambridge, Department of Earth Sciences: ESC Publications
4
University of Cumbria: Insight
4
University of Groningen research database
4
University of Malta: OAR@UM
4
University of New Hampshire: Scholars Repository
4
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