Content Provider
WikiBooks - Open-content textbooks
10
Cambridge University Press
4
Australian National University: ANU Digital Collections
1
RePEc (Research Papers in Economics)
1
Rice University: Digital Scholarship Archive
1
ScholarSpace at University of Hawaii at Manoa
1
Springer Nature (via Crossref)
1
Technical University of Denmark: DTU Orbit
1
University of Western Sydney (UWS): Research Direct
1