Content Provider
University of Michigan: Digital Collections
88
University of Calgary Journal Hosting
45
University of Lethbridge Digitized Collections
42
DataCite Metadata Store (German National Library of Science and Technology)
32
Unknown
28
Connecticut Digital Archive
27
WikiBooks - Open-content textbooks
25
Cambridge University Press
22
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe)
19
Université de Nantes: HAL-UNIV-NANTES
19
MédiHAL
16
Université de Paris: Portail HAL
16
Memorial University of Newfoundland: Digital Archives Initiative (DAI)
15
PubMed Central (PMC)
15
UNESDOC - UNESCO Digital Library
15
Wiley Online Library
15
North Dakota State University (NDSU): Digital Horizons
14
The Library of Congress: American Memory
14
University of Washington, Seattle: Digital Collections
12
Hathi Trust Digital Library
11
The Seattle Public Library Special Collections Online
10
Washington State University: WSU Libraries Digital Collections
10
Érudit.org (Université Montréal)
8
Cambridge University Press (via Crossref)
7
Directory of Open Access Journals: DOAJ Articles
7
Theses Canada/Thèses Canada (Library and Archives Canada)
7
University of Wisconsin, Milwaukee: UWM Libraries Digital Collections
7
AAAS Resource Center (American Association for the Advancement of Science)
6
RePEc (Research Papers in Economics)
6
The Gateway to Oklahoma History (University of North Texas Libraries)
5
Wiley Online Library (via Crossref)
5
York University Digital Library
5
Digitized @ Henry Madden Library (FresnoState)
4
Informa (via Crossref)
4
JSTOR (via Crossref)
4
NOAA NCEI Environmental Data Archive (via DataONE)
4
PRISM - University of Calgary Digital Repository
4
U.S. National Library of Medicine (NLM): Images from the History of Medicine (IHM)
4
University of California: eScholarship
4
Wellcome Trust, London: Wellcome Images
4
Aarhus University: OJS at The State and University Library
3
American Museum of Natural History: AMNH scientific publications
3
Arca (BC's Digital Treasures)
3
Arctic Institute of North America
3
Canadian Science Publishing (via Crossref)
3
JSTOR
3
McGill University: eScholarship@McGill
3
OpenEdition
3
PennState: Digital Collections
3
SAGE Publications (via Crossref)
3
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