Content Provider
DataCite Metadata Store (German National Library of Science and Technology)
42
Copernicus Publications: E-Journals
3
Defense Technical Information Center: DTIC Technical Reports database
2
Unknown
2
Bates College: SCARAB (Scholarly Communication and Research at Bates)
1
Bowdoin College: Bowdoin Digital Commons
1
Digital Repository @ Iowa State University
1
MDPI Open Access Publishing
1
PubMed Central (PMC)
1