Content Provider
LeibnizOpen (The Leibniz Association)
20
Unknown
3
Directory of Open Access Journals: DOAJ Articles
2
Media SuUB Bremen (Staats- und Universitätsbibliothek Bremen)
2
DataCite Metadata Store (German National Library of Science and Technology)
1
Georg-August-Universität Göttingen: GoeScholar
1
Ghent University Academic Bibliography
1
MDPI Open Access Publishing
1
PUB - Publications at Bielefeld University
1
Renate - Repositorium für Naturwissenschaften und Technik (TIB Hannover)
1
University of the Highlands and Islands: Research Database of UHI
1
Zenodo
1