- Electronic Journals Library-University Library of Regensburg, Germany
- Scientific Publications Index
- Scientific Resources Database
- Recent Science Index
- Scholarly Journals Index
- Directory of Academic Resources
- Elite Scientific Journals Archive
- Current Index to Scholarly Journals
- Digital Journals Database
- Academic Papers Database
- Contemporary Research Index
*Scientific Journal Impact Factor
2025: 8.292
2024: 8.127
2023: 5.768
2022: 6.059
2021: 6.199
2020: 6.664
