- BASE (Bielefeld Academic Search Engine)
- Cabell’s Directory
- Cite Seerx | Scientific Literature Digital Library
- CiteULike
- Computer Science Directory
- Electronic Journals Library
- EBSCO Publishing
- EI | engineering village
- ELSEVIER
- Google Scholar
- Google Scholar Metrics
- IET INSPEC
- Index Copernicus
- ISSUU
- Journal ToC
- NewJour | Archives for Journals and Newsletters
- OJS PKP
- Open J-Gate
- ProQuest
- Science Central | Science education for all people
- Scirus | for scientific information
- SCOPUS
- Scribd | The World’s Largest Online Library
- SHERPA/ RoMEO | University of Nottingham
- Socolar Open Access
- University of Zurich Repository
- Ulrich’s Periodicals Directory
- World Wide Science | Global science gateway