Content Provider
DataCite Metadata Store (German National Library of Science and Technology)
1,403
University of Arkansas: Digital Collections
81
The University of Utah: J. Willard Marriott Digital Library
49
University of Arkansas: ScholarWorks@UARK
48
Oklahoma State University: Digital Collections @ OKSTATE Library
42
Unknown
39
Zenodo
30
Defense Technical Information Center: DTIC Technical Reports database
20
WikiBooks - Open-content textbooks
19
PALNI Digital Library Collections (Private Academic Library Network of Indiana)
17
North Dakota State University (NDSU): Digital Horizons
16
Arctic Data Center (via DataONE)
14
Hunter Library Digital Collections (Western Carolina University)
14
JSTOR (via Crossref)
14
Cambridge University Press (via Crossref)
13
Stephen F. Austin State University, Texas: Scholar Works @ SFA
13
University of Nebraska-Lincoln: DigitalCommons@UNL
13
UTSA Digital Collections (The University of Texas at San Antonio)
12
Cambridge University Press
9
David Rumsey Historical Map Collection (Cartography Associates)
9
Directory of Open Access Journals: DOAJ Articles
8
Wiley Online Library
8
ASI Research Portal (Arkansas Studies Institute Catalog)
7
USGS Science Data Catalog (via DataONE)
7
University of Michigan: Digital Collections
6
CDC Stacks (Centers for Disease Control and Prevention)
5
Frontiers: Figshare
5
KovsieScholar Repository (University of the Free State - UFS UV)
5
SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy)
5
University of Lethbridge Digitized Collections
5
University of North Texas: UNT Digital Library
5
the Digital Archaeological Record (via DataONE)
5
Dryad Digital Repository (Duke University)
4
Grand Valley State University: GVSU Digital Collections
4
University of the Pacific, McGeorge School of Law: Scholarly Commons
4
University of the Pacific: Scholarly Commons
4
Australian National University: ANU Digital Collections
3
Canadian Science Publishing (via Crossref)
3
Hathi Trust Digital Library
3
National Institute of Polar Research Repository, Japan
3
Online Research Commons @ATU (Arkansas Tech University)
3
University of Michigan: Deep Blue
3
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe)
2
Athabasca University: AUSpace
2
Baylor University: BEARdocs
2
Earth-Prints (Istituto Nazionale di Geofisica e Vulcanologia)
2
Frontiers (Publisher)
2
HighWire Press (Stanford University)
2
Informa (via Crossref)
2
Loyola University Chicago Digital Special Collections
2
more ...