Content Provider
DataCite Metadata Store (German National Library of Science and Technology)
628
PANGAEA - Data Publisher for Earth & Environmental Science
360
OLAC: Open Language Archives Community
305
Unknown
75
University of Washington, Seattle: Digital Collections
73
APS Digital Library (American Philosophical Society)
31
Hathi Trust Digital Library
27
University of Michigan: Digital Collections
27
Wiley Online Library
27
Biodiversity Heritage Library (BHL)
25
Oxford University Press (via Crossref)
25
WikiBooks - Open-content textbooks
25
Arctic Council Repository
24
PubMed Central (PMC)
22
JSTOR (via Crossref)
20
LeibnizOpen (The Leibniz Association)
20
Oklahoma State University: Digital Collections @ OKSTATE Library
20
The University of Kansas: KU ScholarWorks
19
University of Alaska: ScholarWorks@UA
19
University of Calgary Journal Hosting
19
Cambridge University Press
18
Directory of Open Access Journals: DOAJ Articles
17
NOAA NCEI Environmental Data Archive (via DataONE)
17
Washington State University: WSU Libraries Digital Collections
16
Wiley Online Library (via Crossref)
16
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe)
14
De Gruyter (via Crossref)
14
University of California: eScholarship
14
University of Copenhagen: Research
13
John Benjamins Publishing Company (via Crossref)
12
Utah State University: DigitalCommons@USU
12
Cambridge University Press (via Crossref)
11
SFU Digitized Collections (Simon Fraser University)
11
Université de Nantes: HAL-UNIV-NANTES
11
Creighton University: Creighton Digital Repository (CDR)
10
SAGE Publications (via Crossref)
10
Érudit.org (Université Montréal)
10
HighWire Press (Stanford University)
9
ScienceDirect (Elsevier - via Crossref)
9
University of Chicago Press (via Crossref)
9
Zenodo
9
The University of Utah: J. Willard Marriott Digital Library
8
CyberLeninka (Scientific Electronic Library)
7
Defense Technical Information Center: DTIC Technical Reports database
7
ESS-DIVE: Deep Insight for Earth Science Data (via DataONE)
7
Max Planck Society: MPG.PuRe
7
Arctic Data Center (via DataONE)
6
JSTOR
6
Oregon Digital (University of Oregon/Oregon State University)
6
UI Press - University of Illinois Press (via Crossref)
6
more ...