Free electronic resources
Online portal for general education.
Free journals by Bentham Science Publishers.
Directory of Open Access Journals - online directory that indexes and provides access to quality open access, peer-reviewed journals.
Electronic repository of Institute of mathematics and informatics at Bulgarian academy of sciences.
This site contains doctoral dissertations and other publications from the University of Helsinki.
Free access to European Union Law.
The OpenDOAR service provides a quality-assured listing of open access repositories around the world.
Web search engines
Multi-disciplinary search engine for scientifically relevant web resources which was created and developed by Bielefeld University Library.
Search engine for books.
Search engine for scientific information.
National academic library and information system.
Bibliographic information for documents in different languages and the nearest library they can be found in.