Content Provider
LeibnizOpen (The Leibniz Association)
38
DataCite Metadata Store (German National Library of Science and Technology)
32
Unknown
28
Directory of Open Access Journals: DOAJ Articles
23
WikiBooks - Open-content textbooks
15
Washington State University: WSU Libraries Digital Collections
12
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe)
10
Institute for Marine Research: Brage IMR
10
PubMed Central (PMC)
9
Wiley Online Library
9
Wiley Online Library (via Crossref)
9
Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer)
8
Cambridge University Press
7
University of Tromsø: Munin Open Research Archive
7
Defense Technical Information Center: DTIC Technical Reports database
6
The University of Utah: J. Willard Marriott Digital Library
6
Université de Nantes: HAL-UNIV-NANTES
6
Norwegian Institute for Nature Research: Brage NINA
5
Norwegian Institute for Water research: NIVA Open Access Archive (Brage)
5
PANGAEA - Data Publisher for Earth & Environmental Science
5
ScholarSpace at University of Hawaii at Manoa
5
University of St Andrews: Research Portal
5
University of the Pacific, McGeorge School of Law: Scholarly Commons
5
University of the Pacific: Scholarly Commons
5
CONICET Digital (Consejo Nacional de Investigaciones Científicas y Técnicas)
4
Digital.CSIC (Spanish National Research Council)
4
Ghent University Academic Bibliography
4
HighWire Press (Stanford University)
4
Open archive Norwegian University of Life Sciences: Brage NMBU
4
University of Bergen: Bergen Open Research Archive (BORA-UiB)
4
University of Groningen research database
4
Hathi Trust Digital Library
3
NTNU Open Archive (Norwegian University of Science and Technology)
3
Springer Nature (via Crossref)
3
Technical University of Denmark: DTU Orbit
3
Universitet i Oslo: Digitale utgivelser ved UiO (DUO)
3
Uppsala University: Publications (DiVA)
3
Apollo - University of Cambridge Repository
2
Canadian Science Publishing (via Crossref)
2
Copernicus Publications: E-Journals
2
Flanders Marine Institute (VLIZ): Open Marine Archive (OMA)
2
HAL Sorbonne Université
2
HELDA – University of Helsinki Open Repository
2
Høgskulen på Vestlandet: HVL Open
2
Institut national des sciences de l'Univers: HAL-INSU
2
JYX - Jyväskylä University Digital Archive
2
Jultika - University of Oulu repository
2
MDPI Open Access Publishing
2
Middlesex University London: Research Repository
2
Oxford University Press
2
more ...