Content Provider
DataCite Metadata Store (German National Library of Science and Technology)
462
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel)
71
LeibnizOpen (The Leibniz Association)
62
Unknown
47
Springer Nature (via Crossref)
40
DigiZeitschriften: The German digital journal archive (Göttingen University Library)
38
WikiBooks - Open-content textbooks
38
Biodiversity Heritage Library (BHL)
32
University of Freiburg: FreiDok
32
University of Michigan: Digital Collections
28
Max Planck Society: MPG.PuRe
24
University of Potsdam: publish.UP
22
Directory of Open Access Journals: DOAJ Articles
21
Bavarian Digital Repository (BDR - Bayerische Staatsbibliothek Munich, BSB)
20
EconStor (German National Library of Economics, ZBW)
20
KITopen (Karlsruhe Institute of Technologie)
20
Publication Server of Goethe University Frankfurt am Main
20
Georg-August-Universität Göttingen: GOEDOC
14
GEO-LEOe-docs (FID GEO)
13
da|ra - Registration agency for social and economic data
12
Hathi Trust Digital Library
11
Media SuUB Bremen (Staats- und Universitätsbibliothek Bremen)
11
Zenodo
11
ETH Zürich Research Collection
10
Frankfurt/Main University Library: Digitale Sammlungen
10
Wiley Online Library
10
GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam)
9
e-rara.ch (ETH Zürich)
9
BORIS (Bern Open Repository and Information System, University of Bern)
8
Justus-Liebig-Universität Giessen: JLUpub
8
Publication Server of the Justus-Liebig-University of Giessen
7
University of Vienna: Phaidra
7
ediss.sub.hamburg (Staats- und Universitätsbibliothek Hamburg, Carl von Ossietzky)
7
PUB - Publications at Bielefeld University
6
Publication Database IASS (Institute for Advanced Sustainability Studies Potsdam)
6
University of Groningen research database
6
Wissenschaftliche Verlagsgesellschaft Stuttgart (via Crossref)
6
DIAL@USL-B (Université Saint-Louis, Bruxelles)
5
Directory of Open Access Books (DOAB)
5
Open-Access-Publikationsserver der Humboldt-Universität: edoc-Server
5
OpenAgrar (OA)
5
RWTH Aachen University: RWTH Publications
5
Thieme (via Crossref)
5
Universität der Bundeswehr München: AtheneForschung
5
Forschungszentrum Jülich: JuSER (Juelich Shared Electronic Resources)
4
Gallica - bibliothèque numérique de la Bibliothèque nationale de France (BnF)
4
German Aerospace Center: elib - DLR electronic library
4
Heidelberg University: HeiDok
4
LaCRIS - University of Lapland Current Research System
4
Open Research Library
4
more ...