Content Provider
LeibnizOpen (The Leibniz Association)
30
Unknown
4
DataCite Metadata Store (German National Library of Science and Technology)
3
Directory of Open Access Journals: DOAJ Articles
2
Max Planck Society: MPG.PuRe
2
Renate - Repositorium für Naturwissenschaften und Technik (TIB Hannover)
2
Niedersächsisches Online-Archiv NOA
1