BASE is a multidisciplinary search engine for scholarly internet resources which have been harvested from several hundred scientific repositories. Some of the indexed resources in BASE are subject to license, while most material is free available ("open access").

The EZB is a huge directory of electronic journals which mirrors the central Max Planck Society subscriptions as well as the local licensing situation of the institutes. Access rights to the contents of the individual journals are indicated with "traffic lights". Entries are searchable on journal level.

The GESIS search can be used to find information about social science research data and open access publications. It covers: * Research Data * Variables from questionnaires * Instruments and tools * Literature, incl. publications on research data & surveying instruments, open access publications in the social sciences, as well as literature on the topic "Women in science" * Collections of the GESIS library * GESIS webpages, incl. general information and offers on the GESIS websites

The Max Planck Journal Index provides holdings of a great range of printed journals available within the Max Planck Society. Besides, it contains metadata of electronic journals as loaded from the EZB. The database is updated regularly from the ZDB (twice a year) and the EZB (monthly).

The ZDB is the world’s largest specialized database for serial titles (journals, annuals, newspapers etc., incl. e-journals). The ZDB contains more than 1 million bibliographic records of serials from the 16th century onwards, from all countries, in all languages, held in 4000 German (and some foreign) libraries, with holdings information. It does not index individual journal articles.