BaseBASE provides more than 120 million documents from more than 6,000 sources. Approximately 60% of the indexed documents are Open Access. BASE is operated by Bielefeld University Library. It focusses on high quality academically relevant resources including journal articles, preprints, digital collections, images / videos or research dataYou can browse by DDC (Dewey Decimal Classification), document type, access and terms of re-use / licence.