Content Provider
DataCite Metadata Store (German National Library of Science and Technology)
499
University of Lethbridge Digitized Collections
119
PALNI Digital Library Collections (Private Academic Library Network of Indiana)
114
North Dakota State University (NDSU): Digital Horizons
112
Memorial University of Newfoundland: Digital Archives Initiative (DAI)
87
The University of Utah: J. Willard Marriott Digital Library
46
Unknown
25
Hunter Library Digital Collections (Western Carolina University)
24
University of Washington, Seattle: ResearchWorks
23
Directory of Open Access Journals: DOAJ Articles
21
Biodiversity Heritage Library (BHL)
18
The University of Alabama at Birmingham: UAB Libraries' Digital Collections
18
UTSA Digital Collections (The University of Texas at San Antonio)
18
CyberLeninka (Scientific Electronic Library)
17
Hathi Trust Digital Library
17
Washington State University: WSU Libraries Digital Collections
17
WikiBooks - Open-content textbooks
17
Defense Technical Information Center: DTIC Technical Reports database
15
Loyola University Chicago Digital Special Collections
14
NOAA NCEI Environmental Data Archive (via DataONE)
14
Oklahoma State University: Digital Collections @ OKSTATE Library
13
University of Alaska: ScholarWorks@UA
13
University of Washington, Seattle: Digital Collections
12
Cambridge University Press
11
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe)
10
University of Nebraska-Lincoln: DigitalCommons@UNL
8
Université de Nantes: HAL-UNIV-NANTES
8
Bavarian Digital Repository (BDR - Bayerische Staatsbibliothek Munich, BSB)
7
Saint Louis University Libraries Digital Collections
7
University of Calgary Journal Hosting
7
Ball State University: Digital Media Repository
6
Institut national des sciences de l'Univers: HAL-INSU
6
Oxford University Press (via Crossref)
6
University of the Pacific, McGeorge School of Law: Scholarly Commons
6
University of the Pacific: Scholarly Commons
6
Creighton University: Creighton Digital Repository (CDR)
5
David Rumsey Historical Map Collection (Cartography Associates)
5
DergiPark Akademik (E-Journals)
5
HAL Sorbonne Université
5
Memorial University of Newfoundland: Research Repository
5
PANGAEA - Data Publisher for Earth & Environmental Science
5
SLUB Dresden: Collections (Saxon State Library - State and University Library Dresden)
5
Zenodo
5
Archives ouvertes de Paris-Saclay
4
Ike Skelton Combined Arms Research Library (CARL) Digital Library
4
Muséum National d'Histoire Naturelle (MNHM): HAL
4
Our@Oakland
4
SDSUnbound (San Diego State University)
4
Université de Paris: Portail HAL
4
Université de Versailles Saint-Quentin-en-Yvelines: HAL-UVSQ
4
more ...