Content Provider
Directory of Open Access Journals: DOAJ Articles
57
Unknown
37
Copernicus Publications: E-Journals
24
DataCite Metadata Store (German National Library of Science and Technology)
22
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe)
19
Niedersächsisches Online-Archiv NOA
17
Defense Technical Information Center: DTIC Technical Reports database
15
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel)
15
PANGAEA - Data Publisher for Earth & Environmental Science
14
Université de Nantes: HAL-UNIV-NANTES
14
Institut national des sciences de l'Univers: HAL-INSU
13
MDPI Open Access Publishing
13
WikiBooks - Open-content textbooks
12
North Dakota State University (NDSU): Digital Horizons
9
Tomsk State University Research Library
8
PubMed Central (PMC)
7
University of Calgary Journal Hosting
7
Wiley Online Library
7
University of the Pacific, McGeorge School of Law: Scholarly Commons
6
University of the Pacific: Scholarly Commons
6
Cambridge University Press
5
Washington State University: WSU Libraries Digital Collections
5
Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server)
5
HAL Sorbonne Université
4
Hathi Trust Digital Library
4
Max Planck Society: MPG.PuRe
4
Northumbria University, Newcastle: Northumbria Research Link (NRL)
4
Texas A&M University Digital Repository
4
Umeå University: Publications (DiVA)
4
Wiley Online Library (via Crossref)
4
Aarhus University: Research
3
HELDA – University of Helsinki Open Repository
3
Hereon Publications (Helmholtz-Zentrum)
3
Hokkaido University Collection of Scholarly and Academic Papers (HUSCAP)
3
Lund University Publications (LUP)
3
Macquarie University Research Portal
3
Météo-France: HAL
3
University of Potsdam: publish.UP
3
Université Toulouse III - Paul Sabatier: HAL-UPS
3
Université de Versailles Saint-Quentin-en-Yvelines: HAL-UVSQ
3
Utrecht University Repository
3
Archive de l'Observatoire de Paris (HAL)
2
Archives ouvertes de Paris-Saclay
2
ETH Zürich Research Collection
2
Freie Universität Berlin: Refubium (FU Berlin)
2
German Aerospace Center: elib - DLR electronic library
2
Jultika - University of Oulu repository
2
LeibnizOpen (The Leibniz Association)
2
Media SuUB Bremen (Staats- und Universitätsbibliothek Bremen)
2
NORA (National aggregator of open repositories of Russian universities)
2
more ...