Content Provider
Memorial University of Newfoundland: Digital Archives Initiative (DAI)
231,906
PANGAEA - Data Publisher for Earth & Environmental Science
128,637
Directory of Open Access Journals: DOAJ Articles
111,699
DataCite Metadata Store (German National Library of Science and Technology)
76,360
Unknown
56,996
DataCite
51,256
Wiley Online Library
41,282
ScienceDirect (Elsevier - via Crossref)
28,642
Springer Nature (via Crossref)
27,011
PubMed Central (PMC)
26,043
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe)
23,295
Cambridge University Press
23,091
ScienceDirect (Elsevier)
19,684
Université de Nantes: HAL-UNIV-NANTES
14,833
Copernicus Publications: E-Journals
13,790
LeibnizOpen (The Leibniz Association)
12,765
Institut national des sciences de l'Univers: HAL-INSU
12,608
Open Parks Network
12,595
Defense Technical Information Center: DTIC Technical Reports database
11,329
Niedersächsisches Online-Archiv NOA
9,807
Informa (via Crossref)
9,680
Informa
9,557
MDPI Open Access Publishing
8,594
HighWire Press (Stanford University)
7,638
National Institute of Polar Research Repository, Japan
7,551
University of Copenhagen: Research
7,438
Aarhus University: Research
6,954
Oxford University Press
6,639
University of Tromsø: Munin Open Research Archive
6,534
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel)
6,499
Hathi Trust Digital Library
6,042
eCite UTAS (University of Tasmania)
6,002
Wiley Online Library (via Crossref)
5,888
Natural Environment Research Council: NERC Open Research Archive
5,851
Canadian Science Publishing
5,819
HAL Sorbonne Université
5,463
Zenodo
5,269
Digital.CSIC (Spanish National Research Council)
5,212
University of Calgary Journal Hosting
5,137
University of St Andrews: Research Portal
5,062
Canadian Science Publishing (via Crossref)
4,918
WikiBooks - Open-content textbooks
4,558
Technical University of Denmark: DTU Orbit
4,268
Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer)
4,267
Memorial University of Newfoundland: Research Repository
4,195
Biodiversity Heritage Library (BHL)
4,070
Arctic Council Repository
3,993
Ohio State University (OSU): Knowledge Bank
3,683
Université de Versailles Saint-Quentin-en-Yvelines: HAL-UVSQ
3,571
Oxford University Press (via Crossref)
3,437
more ...