- Web of Science
- Scopus
- MathSciNet
- SISSA Preprints archive
- SISSA Articles acquisition (available only through SISSA network).
- zbMATH - ZentralblattMATH
- Jahrbuch Project (Jahrbuch über die Fortschritte der Mathematik) 1868-1942
- Dimensions(Digital Science)
- INSPIRE (high-energy physics)
- arXiv
- ADS - the NASA Astrophysics Data System
- Preprints in Technology Research ( TechRxiv.org, is a free preprints repository of the IEEE in electrical engineering, computer science, and related technologies)
- Preprint Server for Biology
- Earth Science preprints
- Engineering preprints archive
- Open archive for social sciences
- Cogprints
- Preprint service for the psychological sciences
- Preprints and post-print repository of scholarly legal content
- International Nuclear Information System (INIS-IAEA)
- PubMed (MEDLINE Database)
- PubChem
- External preprint archives