Content Provider
DataCite Metadata Store (German National Library of Science and Technology)
3
Directory of Open Access Journals: DOAJ Articles
1
LeibnizOpen (The Leibniz Association)
20
Niedersächsisches Online-Archiv NOA
1
ScienceDirect (Elsevier - via Crossref)
1
Springer Nature (via Crossref)
1
Stockholm University Press
4
University of Copenhagen: Research
1
Unknown
3
York University, Toronto: YorkSpace
1