Content Provider
Apollo - University of Cambridge Repository
1
Clark University: Clark Digital Commons
1
DataCite Metadata Store (German National Library of Science and Technology)
1
Directory of Open Access Journals: DOAJ Articles
5
LeibnizOpen (The Leibniz Association)
39
MDPI Open Access Publishing
5
National Research Council Canada: NRC Publications Archive
1
Norwegian Polar Data Centre
1
Pensoft Publishers
1
Peoples' Friendship University of Russia (RUDN): Open repository
1
Renate - Repositorium für Naturwissenschaften und Technik (TIB Hannover)
1
Saint Petersburg State University: Research Repository (DSpace SPbU)
1
Sapienza Università di Roma: CINECA IRIS
1
Unknown
11