Content Provider
ScienceDirect (Elsevier - via Crossref)
91
ScienceDirect (Elsevier)
56
Frontiers: Figshare
31
DataCite Metadata Store (German National Library of Science and Technology)
28
Directory of Open Access Journals: DOAJ Articles
13
Institute of Oceanology, Chinese Academy of Sciences: IOCAS-IR
9
Frontiers (Publisher)
8
Nanjing Institute of Geology and Palaeontology: NIGPAS OpenIR (Chinese Academy of Sciences)
8
Old Dominion University: ODU Digital Commons
8
Wiley Online Library
7
Utrecht University Repository
6
Australian National University: ANU Digital Collections
5
eCite UTAS (University of Tasmania)
5
The Royal Society: Figshare
3
The University of Queensland: UQ eSpace
3
University of St Andrews: Digital Research Repository
3
Unknown
3
Wiley Online Library (via Crossref)
3
Biblioteca Digital FCEN-UBA (Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires)
2
Columbia University: Academic Commons
2
RUcore - Rutgers University Community Repository
2
Springer Nature (via Crossref)
2
University College London: UCL Discovery
2
Università degli Studi di Bari Aldo Moro: CINECA IRIS
2
Archivio della ricerca dell'Università di Modena e Reggio Emilia (Unimore: IRIS)
1
Cambridge University Press
1
Digital.CSIC (Spanish National Research Council)
1
Edith Cowan University (ECU, Australia): Research Online
1
Florida State University Digital Library (FSUDL)
1
Florida State University: DigiNole Commons
1
IRIS Università degli Studi di Palermo
1
Informa
1
Lund University Publications (LUP)
1
Mary Immaculate College (University of Limerick): Institutional Repository and Digital Archive
1
National Archive of PhD Theses (National Documentation Centre Greece)
1
Oxford University Press
1
Texas A&M University Digital Repository
1
The University of Milan: Archivio Istituzionale della Ricerca (AIR)
1
UNESDOC - UNESCO Digital Library
1
Universidade do Algarve: Sapienta
1
University at Albany, State University of New York (SUNY): Scholars Archive
1
University of California: eScholarship
1
University of Cape Town: OpenUCT
1
University of Nebraska-Lincoln: DigitalCommons@UNL
1
University of Rhode Island: DigitalCommons@URI
1
Università Politecnica delle Marche: IRIS
1
Università degli studi di Torino: AperTo (Archivio Istituzionale ad Accesso Aperto)
1