Content Provider
Dryad Digital Repository (Duke University)
84
University of Alaska: ScholarWorks@UA
78
DataCite Metadata Store (German National Library of Science and Technology)
36
Arctic Data Center (via DataONE)
29
Washington State University: WSU Libraries Digital Collections
16
Defense Technical Information Center: DTIC Technical Reports database
9
Oregon Digital (University of Oregon/Oregon State University)
9
Unknown
8
University of Michigan: Digital Collections
4
Copernicus Publications: E-Journals
3
NASA Technical Reports Server (NTRS)
3
Cambridge University Press
2
Directory of Open Access Journals: DOAJ Articles
2
Kazan Federal University Digital Repository
2
NORA (National aggregator of open repositories of Russian universities)
2
Ohio State University (OSU): Knowledge Bank
2
SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy)
2
University of Lethbridge Digitized Collections
2
University of Nebraska-Lincoln: DigitalCommons@UNL
2
University of North Texas: UNT Digital Library
2
University of Washington, Seattle: Digital Collections
2
Wageningen UR (University & Research Centre): Digital Library
2
Wiley Online Library
2
AAAS Resource Center (American Association for the Advancement of Science)
1
Arctic Council Repository
1
Canadian Science Publishing (via Crossref)
1
ESS-DIVE: Deep Insight for Earth Science Data (via DataONE)
1
Hathi Trust Digital Library
1
MDPI Open Access Publishing
1
Niedersächsisches Online-Archiv NOA
1
Oxford University Press (via Crossref)
1
Portland Public Library: Digital Commons
1
University of Calgary Journal Hosting
1
University of Colorado, Boulder: CU Scholar
1
University of Florida: Digital Library Center
1
University of Nevada, Reno: ScholarWorks Repository
1
Washington Rural Heritage (Washington State Library)
1
Washington State Library: Digital Collections and Resources
1
Xiamen University Institutional Repository
1