Content Provider
DataCite Metadata Store (German National Library of Science and Technology)
106,488
Directory of Open Access Journals: DOAJ Articles
51,162
PANGAEA - Data Publisher for Earth & Environmental Science
16,254
Unknown
15,782
Arctic Data Center (via DataONE)
12,762
Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center)
6,154
Springer Nature (via Crossref)
5,846
Zenodo
5,594
ScienceDirect (Elsevier - via Crossref)
5,167
PubMed Central (PMC)
3,827
Defense Technical Information Center: DTIC Technical Reports database
3,556
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe)
3,537
Copernicus Publications: E-Journals
3,533
Open Parks Network
3,531
LeibnizOpen (The Leibniz Association)
3,065
Wiley Online Library (via Crossref)
2,943
Cambridge University Press
2,702
Informa (via Crossref)
2,593
Niedersächsisches Online-Archiv NOA
2,394
Wiley Online Library
2,365
University of Tromsø: Munin Open Research Archive
2,280
Arctic Council Repository
2,212
University of Calgary Journal Hosting
2,129
Université de Nantes: HAL-UNIV-NANTES
2,067
MDPI Open Access Publishing
1,993
SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy)
1,933
Aarhus University: Research
1,927
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel)
1,825
Biodiversity Heritage Library (BHL)
1,763
CyberLeninka (Scientific Electronic Library)
1,746
NOAA NCEI Environmental Data Archive (via DataONE)
1,701
ScienceDirect (Elsevier)
1,490
Dryad Digital Repository (Duke University)
1,382
Institut national des sciences de l'Univers: HAL-INSU
1,340
RePEc (Research Papers in Economics)
1,326
Canadian Science Publishing (via Crossref)
1,319
Frontiers: Figshare
1,190
University of Wisconsin, Milwaukee: UWM Libraries Digital Collections
1,188
University of Michigan: Digital Collections
1,161
University of California: eScholarship
1,144
Springer Nature
1,139
Natural Environment Research Council: NERC Open Research Archive
1,067
Hathi Trust Digital Library
1,056
NASA Technical Reports Server (NTRS)
1,047
IOP Publishing (via Crossref)
1,036
LaCRIS - University of Lapland Current Research System
1,033
University of Alaska: ScholarWorks@UA
1,030
University of Copenhagen: Research
1,005
Max Planck Society: MPG.PuRe
951
JSTOR (via Crossref)
939
more ...