1. Google Scholar

2. DOAJ Directory Of Open Access Journals

3. SINTA_ristek Dikti

4. Moraref

5. Indonesian Publication Index (IPI)

6. GARUDA-Garba Rujukan Digital

7. Euro Pub-Directory: Of Academic and Scientific Journals

8. Scientific and Technical Information Portal-TN

9. Maktaba

10. Open Science Directory

11. Mendeley

12. International Standard Serial Number

13. Worldcat

14. Universiteits Biblio Theek Gent

15. Base (Biefeld Academic Search Engine)