Content Provider
Biodiversity Heritage Library (BHL)
11
WikiBooks - Open-content textbooks
7
Cambridge University Press
5
Memorial University of Newfoundland: Digital Archives Initiative (DAI)
5
Unknown
3
University of Copenhagen: Research
2
Aisberg - Archivio istituzionale dell'Università di Bergamo
1
American Museum of Natural History: AMNH scientific publications
1
Oxford University Press
1
Oxford University Press (via Crossref)
1
Publication Server of Goethe University Frankfurt am Main
1
Texas Tech University: Southwest Collection/Special Collections Library
1
UNESDOC - UNESCO Digital Library
1
University of North Texas: UNT Digital Library
1
University of Otago: OUR Heritage (Otage University Research)
1