1. Copernicus

2. DOAJ

3. Google Scholar

4. SINTA_ristek Dikti (Sinta 4)

5. Moraref

6. Dimensions

7. GARUDA-Garba Rujukan Digital

8. International Standard Serial Number

9. OneSearch Indonesia

10. Crossref

11. Leiden University Library

12. Boston University Library

13. University Library

14. Standford Libraries

15. Harvard Library

16. BASE (Bielefeld Academic Search Engine)

17. Semantic Scholar