Content Provider
University of Michigan: Digital Collections
21
Unknown
9
DataCite Metadata Store (German National Library of Science and Technology)
8
PANGAEA - Data Publisher for Earth & Environmental Science
6
University of Calgary Journal Hosting
5
Cambridge University Press
4
University of Wisconsin, Milwaukee: UWM Libraries Digital Collections
4
APA Publishing (American Psychological Association)
2
Directory of Open Access Journals: DOAJ Articles
2
Arctic Institute of North America
1
Arctic Institute of North America (via Crossref)
1
Connecticut Digital Archive
1
Dalhousie University: DalSpace Institutional Repository
1
De Gruyter (via Crossref)
1
PubMed Central (PMC)
1