1. World Cat
2. Crossref
3. Scilit
4. Sherpa/Romeo
5. Indonesian Scientific Journal Database (ISJD)
6. Google Scholar
7. Directory of Open Access Journals
8. Lancaster University
9. Bielefeld Academic Search Engine (BASE)
10. British Library
11. Mendeley
12. Science and Technology Index (SINTA)
13. Garda Rujukan Digital (Garuda)
14. i-Journal UdlEdge
15. i-Focus UdlEdge