Content Provider
DataCite Metadata Store (German National Library of Science and Technology)
316
DataCite
132
LeibnizOpen (The Leibniz Association)
129
CyberLeninka (Scientific Electronic Library)
95
Directory of Open Access Journals: DOAJ Articles
85
Zenodo
52
Unknown
41
Wiley Online Library
38
Aarhus University: Research
36
Springer Nature (via Crossref)
30
PubMed Central (PMC)
24
IRUA - Institutional Repository van de Universiteit Antwerpen
20
LAEI VL (Lithuanian Institute of Agrarian Economics Virtual Library)
16
LSRC VL (Lithuanian Social Research Centre Virtual Library)
16
Frankfurt/Main University Library: Digitale Sammlungen
15
NTNU Open Archive (Norwegian University of Science and Technology)
13
Norwegian Institute for Nature Research: Brage NINA
13
ScienceDirect (Elsevier - via Crossref)
11
University of Turku: UTUPub
11
Federation of Finnish Learned Societies: Scientific Journals Online
10
ScienceDirect (Elsevier)
10
University of Copenhagen: Research
10
University of Tromsø: Munin Open Research Archive
10
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe)
9
Cardiff University: ORCA (Online Research @ Cardiff)
9
Vilnius University Virtual Library (VU VL)
8
BioOne Online Journals
7
PUBLISSO Fachrepositorium Lebenswissenschaften (ZB MED)
7
University of Liège: ORBi (Open Repository and Bibliography)
7
Wiley Online Library (via Crossref)
7
Croatian Digital Theses Repository (National and University Library in Zagreb)
6
Digital.CSIC (Spanish National Research Council)
6
Flanders Marine Institute (VLIZ): Open Marine Archive (OMA)
6
Freie Universität Berlin: Refubium (FU Berlin)
6
MDPI Open Access Publishing
6
University of the Balearic Islands (UIB): Digital Library
6
Université de Nantes: HAL-UNIV-NANTES
6
ACS Publications
5
Biodiversity Heritage Library (BHL)
5
De Gruyter
5
HELDA – University of Helsinki Open Repository
5
Informa
5
Informa (via Crossref)
5
Jultika - University of Oulu repository
5
NILU – Norwegian Institute for Air Research: NILU Brage
5
Sciendo (de Gruyter - via CrossRef)
5
Swedish University of Agricultural Sciences (SLU): Epsilon Open Archive
5
Bergen Open Access Publishing (University of Bergen Library)
4
De Gruyter (via Crossref)
4
Dryad Digital Repository (Duke University)
4
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