Content Provider
WikiBooks - Open-content textbooks
5
Bavarian Digital Repository (BDR - Bayerische Staatsbibliothek Munich, BSB)
4
DataCite Metadata Store (German National Library of Science and Technology)
3
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel)
2
Publication Server of Goethe University Frankfurt am Main
2
e-rara.ch (ETH Zürich)
2
DIAL@USL-B (Université Saint-Louis, Bruxelles)
1
Staatsbibliothek zu Berlin: Digitised Collections
1
WDB - Wolfenbüttel Digital Library (HAB - Herzog-August-Bibliothek Wolfenbüttel)
1