Content Provider
Biodiversity Heritage Library (BHL)
192
IODE-UNESCO: OceanDocs - E-Repository of Ocean Publications
77
International Association of Aquatic and Marine Science Libraries and Information Centers (IAMSLIC): Aquatic Commons
69
WikiBooks - Open-content textbooks
12
OpenAgrar (OA)
5
Oxford University Press (via Crossref)
5
DataCite Metadata Store (German National Library of Science and Technology)
2
David Rumsey Historical Map Collection (Cartography Associates)
2
Arctic Portal Library
1
Cambridge University Press
1
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel)
1
Oxford University Press
1
Pensoft Publishers
1
Smithsonian Institution: Figshare
1
Texas Tech University: Southwest Collection/Special Collections Library
1
The National Academies Press (via Crossref)
1
UNESDOC - UNESCO Digital Library
1
University of Liège: ORBi (Open Repository and Bibliography)
1
University of Toronto Press (U Toronto Press - via Crossref)
1
University of Washington, Seattle: ResearchWorks
1
Uppsala University: Publications (DiVA)
1