Content Provider
DataCite Metadata Store (German National Library of Science and Technology)
2
Directory of Open Access Journals: DOAJ Articles
2
University of Calgary Journal Hosting
2
Copernicus Publications: E-Journals
1
ENEA-IRIS Open Archive (Agenzia nazionale per le nuove tecnologie, l'energia e lo sviluppo economico sostenibile)
1
MDPI Open Access Publishing
1
National Research Council Canada: NRC Publications Archive
1
Niedersächsisches Online-Archiv NOA
1
Unknown
1