Content Provider
ScienceDirect (Elsevier - via Crossref)
18
Wiley Online Library
14
Wiley Online Library (via Crossref)
12
Directory of Open Access Journals: DOAJ Articles
9
ScienceDirect (Elsevier)
8
Schweizerbart Science Publishers (via Crossref)
3
Schweizerbart Science Publishers
2
Springer Nature (via Crossref)
2
ARPI - Archivio della Ricerca dell'Università di Pisa
1
Utrecht University Repository
1