• EDIT

The Repository Common Search Service 

• ERIC - Education Resources Information Center

ERIC is an online library of education research and information, sponsored by the Institute of Education Sciences (IES) of the U.S. Department of Education.

• FIS Bildung Fachportal Pädagogik

Die FIS Bildung Literaturdatenbank bietet Literaturnachweise zu allen Teilbereichen des Bildungswesens.

• OAI (Open Archives Initiative)

Searchable and citable electronic archives and database of periodicals

• EUROPEANA

The European Digital Library 

• The Core Open Access Database 

The world’s largest collection of open access research papers 

• OPKM

The National Educational Library and Museum of Hungary 

• MOKKA

The National Common Catalogue of Hungary