Content Provider
Directory of Open Access Journals: DOAJ Articles
8,495
DataCite Metadata Store (German National Library of Science and Technology)
6
Directory of Open Access Journals: DOAJ Journals
5
Zenodo
4
DataCite
3
Apollo - University of Cambridge Repository
2
Carolina Digital Repository (UNC - University of North Carolina)
1
Doria (National Library of Finland)
1
Unknown
1