Content Provider
Open Parks Network
1,033
Washington State University: WSU Libraries Digital Collections
123
University of Alaska: ScholarWorks@UA
99
DataCite Metadata Store (German National Library of Science and Technology)
29
Oklahoma State University: Digital Collections @ OKSTATE Library
15
Unknown
12
Defense Technical Information Center: DTIC Technical Reports database
11
University of Lethbridge Digitized Collections
9
Cambridge University Press
8
University of Calgary Journal Hosting
8
PubMed Central (PMC)
4
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe)
3
Canadian Science Publishing (via Crossref)
3
Directory of Open Access Journals: DOAJ Articles
3
WikiBooks - Open-content textbooks
3
Arctic Council Repository
2
Canadian Science Publishing
2
Hathi Trust Digital Library
2
Hunter Library Digital Collections (Western Carolina University)
2
Institut national des sciences de l'Univers: HAL-INSU
2
University of Alberta: Era - Education and Research Archive
2
University of North Texas: UNT Digital Library
2
BioMed Central
1
CDC Stacks (Centers for Disease Control and Prevention)
1
Cambridge University Press (via Crossref)
1
Copernicus Publications: E-Journals
1
DataCite
1
Gallica - bibliothèque numérique de la Bibliothèque nationale de France (BnF)
1
Harvard University: DASH - Digital Access to Scholarship at Harvard
1
Niedersächsisches Online-Archiv NOA
1
North Dakota State University (NDSU): Digital Horizons
1
Ohio State University (OSU): Knowledge Bank
1
PANGAEA - Data Publisher for Earth & Environmental Science
1
Texas Tech University: TTU DSpace Repository
1
UTSA Digital Collections (The University of Texas at San Antonio)
1
University of Chicago Press (via Crossref)
1
University of Tennessee, Knoxville: Scholarly Communication Services
1
University of Washington, Seattle: Digital Collections
1
University of Washington, Seattle: ResearchWorks
1
University of Wisconsin, Milwaukee: UWM Libraries Digital Collections
1
Université de Nantes: HAL-UNIV-NANTES
1
Wiley Online Library
1
Xiamen University Institutional Repository
1