Content Provider
DataCite Metadata Store (German National Library of Science and Technology)
103
Arctic Data Center (via DataONE)
98
DataCite
73
Defense Technical Information Center: DTIC Technical Reports database
72
PANGAEA - Data Publisher for Earth & Environmental Science
54
Directory of Open Access Journals: DOAJ Articles
48
Unknown
42
Cambridge University Press
34
Copernicus Publications: E-Journals
34
Zenodo
32
University of Copenhagen: Research
30
University of Wisconsin, Milwaukee: UWM Libraries Digital Collections
23
Wiley Online Library
23
Niedersächsisches Online-Archiv NOA
19
Technical University of Denmark: DTU Orbit
19
Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center)
18
University of Washington, Seattle: Digital Collections
17
Aarhus University: Research
15
University of Calgary Journal Hosting
15
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe)
14
Aarhus University: OJS at The State and University Library
13
NASA Technical Reports Server (NTRS)
13
Tidsskrift.dk (The Royal Library, Denmark)
13
Hathi Trust Digital Library
12
Ohio State University (OSU): Knowledge Bank
10
ScienceDirect (Elsevier - via Crossref)
10
Université de Nantes: HAL-UNIV-NANTES
10
German Aerospace Center: elib - DLR electronic library
9
Institut national des sciences de l'Univers: HAL-INSU
9
National Institute of Polar Research Repository, Japan
9
University of Michigan: Digital Collections
9
Utrecht University Repository
9
AAAS Resource Center (American Association for the Advancement of Science)
8
Natural Environment Research Council: NERC Open Research Archive
8
Lund University Publications (LUP)
7
BORIS (Bern Open Repository and Information System, University of Bern)
6
Caltech Authors (California Institute of Technology)
6
Hokkaido University Collection of Scholarly and Academic Papers (HUSCAP)
6
Springer Nature (via Crossref)
6
University of New Hampshire: Scholars Repository
6
Università Ca’ Foscari Venezia: ARCA (Archivio Istituzionale della Ricerca)
6
Université Grenoble Alpes: HAL
6
PubMed Central (PMC)
5
University College London: UCL Discovery
5
Université Savoie Mont Blanc: HAL
5
Apollo - University of Cambridge Repository
4
Archives ouvertes de Paris-Saclay
4
Biodiversity Heritage Library (BHL)
4
Canadian Science Publishing (via Crossref)
4
Durham University: Durham Research Online
4
more ...