Content Provider
University of Washington, Seattle: Digital Collections
14
DataCite Metadata Store (German National Library of Science and Technology)
5
David Rumsey Historical Map Collection (Cartography Associates)
4
Washington State University: WSU Libraries Digital Collections
2
Wiley Online Library
2
Canadian Science Publishing
1
Canadian Science Publishing (via Crossref)
1
Digital Repository @ Iowa State University
1
Directory of Open Access Journals: DOAJ Articles
1
National Research Council Canada: NRC Publications Archive
1
Oxford University Press (via Crossref)
1
The Library of Congress: American Memory
1
Universitet i Oslo: Digitale utgivelser ved UiO (DUO)
1
University of Calgary Journal Hosting
1
Unknown
1