Content Provider
PubMed Central (PMC)
829
University of Calgary Journal Hosting
147
Georgetown University: DigitalGeorgetown
51
Biodiversity Heritage Library (BHL)
37
CDC Stacks (Centers for Disease Control and Prevention)
31
Open Parks Network
28
UNESDOC - UNESCO Digital Library
26
Hathi Trust Digital Library
25
HighWire Press (Stanford University)
25
University of North Texas: UNT Digital Library
20
Maine State Documents (Maine State Library)
18
Unknown
14
DataCite Metadata Store (German National Library of Science and Technology)
10
Zenodo
10
Directory of Open Access Journals: DOAJ Articles
9
Ike Skelton Combined Arms Research Library (CARL) Digital Library
9
Hirsla - Landspítali University Hospital research archive
7
Temple University Digital Collections
7
University of Wisconsin, Milwaukee: UWM Libraries Digital Collections
7
Stellenbosch University: SUNScholar Research Repository
6
da|ra - Registration agency for social and economic data
6
Digital.CSIC (Spanish National Research Council)
5
Florida State University Digital Library (FSUDL)
5
Instituto Español de Oceanografía: e-IEO
5
Northern Arizona University (NAU): Special Collections and Archives
5
PUBLISSO Fachrepositorium Lebenswissenschaften (ZB MED)
5
Apollo - University of Cambridge Repository
4
Skemman (Iceland)
4
University of Alberta: Era - Education and Research Archive
4
University of Southern Denmark Research Portal
4
WHO (World Health Organization): Institutional Repository for Information Sharing (IRIS)
4
Aarhus University: Research
3
Arca (BC's Digital Treasures)
3
Biblioteca Digital FCEN-UBA (Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires)
3
Carleton University's Institutional Repository
3
Flanders Marine Institute (VLIZ): Open Marine Archive (OMA)
3
Opin vísindi (Iceland)
3
VTechWorks (VirginiaTech)
3
APS Digital Library (American Philosophical Society)
2
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe)
2
Dalhousie University: DalSpace Institutional Repository
2
Emily Carr University's eCollections (ECUAD)
2
IMHE OpenIR (Institute of Mountain Hazards and Environment, Chinese Academy of Sciences)
2
Loughborough University Library Open Journals
2
OpenAgrar (OA)
2
Oregon Digital (University of Oregon/Oregon State University)
2
Repositorio Universidad Autónoma de Bucaramanga
2
The University of Adelaide: Digital Library
2
The University of Western Ontario: Scholarship@Western
2
UNM Digital Repository (The University of New Mexico)
2
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