Content Provider
DataCite Metadata Store (German National Library of Science and Technology)
367
Zenodo
55
Dryad Digital Repository (Duke University)
45
Directory of Open Access Journals: DOAJ Articles
43
University of Tromsø: Munin Open Research Archive
38
Unknown
34
Norwegian Institute for Nature Research: Brage NINA
21
PubMed Central (PMC)
17
NTNU Open Archive (Norwegian University of Science and Technology)
13
WikiBooks - Open-content textbooks
11
Open archive Norwegian University of Life Sciences: Brage NMBU
10
Data Archiving and Networked Services (DANS): EASY (KNAW - Koninklijke Nederlandse Akademie van Wetenschappen)
9
MDPI Open Access Publishing
9
Umeå University: Publications (DiVA)
8
Universitet i Oslo: Digitale utgivelser ved UiO (DUO)
8
HELDA – University of Helsinki Open Repository
7
Høgskolen i Innlandet: Brage INN
7
UNESDOC - UNESCO Digital Library
7
Aarhus University: Research
6
Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center)
6
Ike Skelton Combined Arms Research Library (CARL) Digital Library
6
University of Bergen: Bergen Open Research Archive (BORA-UiB)
6
Informa (via Crossref)
5
North Dakota State University (NDSU): Digital Horizons
5
PANGAEA - Data Publisher for Earth & Environmental Science
5
Cambridge University Press
4
LaCRIS - University of Lapland Current Research System
4
Lund University Publications (LUP)
4
Wiley Online Library
4
Arctic Data Center (via DataONE)
3
Canadian Science Publishing (via Crossref)
3
Copernicus Publications: E-Journals
3
Ghent University Academic Bibliography
3
Helsingfors Universitet: HELDA – Helsingin yliopiston digitaalinen arkisto
3
National Institute of Polar Research Repository, Japan
3
Open archive Nord universitet
3
RePEc (Research Papers in Economics)
3
University of Copenhagen: Research
3
University of Southampton: e-Prints Soton
3
University of Stirling: Stirling Digital Research Repository
3
University of Turku: UTUPub
3
Uppsala University: Publications (DiVA)
3
Wiley Online Library (via Crossref)
3
AMUR - Adam Mickiewicz University Repository, Poznan
2
Apollo - University of Cambridge Repository
2
Cambridge University Press (via Crossref)
2
Canadian Science Publishing
2
Charles University CU Digital repository
2
Jultika - University of Oulu repository
2
Kazan Federal University Digital Repository
2
more ...