Das Biographisch-Bibliographische Kirchenlexikon (BBKL) ist ein biographisches Nachschlagewerk zur Kirchengeschichte, begründet 1975 von Friedrich Wilhelm Bautz. Mit über 20.000 Artikeln, die sowohl von renommierten Wissenschaftlern als auch von interessierten Laien verfasst wurden, gilt das BBKL als sehr aktuelle und umfangreiche biographische Informationsquelle zu Personen der Kirchen-, aber auch der Philosophiegeschichte. Nur der auf knappe Kurzinformationen beschränkte biografische Teil der BBKL ist kostenfrei zugänglich, der Rest ist lizenzpflichtig.

MIA contains the writings of 592 authors representing a complete spectrum of political, philosophical, and scientific thought, generally spanning the past 200 years. Being a communist means working for the self-emancipation of the working class; it means striving to unite the working class, in all its diversity, in the struggle to overthrow capitalism. In the 1840s, Marx and Engels placed communism on a scientific footing through the theory of dialectical materialism. Marxists are those who have continued this ever since. If any one of the following criteria apply, the MIA Collective may decide to place the writer into the Reference Archive: (i) they pre-date Marx and Engels, (ii) they specifically reject Marxism, (iii) their work is practically and theoretically unconnected or hostile toward the workers movement, (iv) their work is idealistic or lacking in dialectic. Where a writer contributes to Marxist theory and practice for a part of their life, while other works lie outside of Marxism, then the whole of their writing will be placed in the Marxist Writers' Archive.Contains: Karl Marx/ Friedrich Engels - Werke ; Rosa Luxenburg; August Bebel; Antonio Gramsci ...

The SpringerLink platform provides MPG staff with access to a huge collection of English and German eBooks from 2005 onwards, as well as the English and the German collection of the Springer Book Archive (1842-2004). In addition, the content of selected book series is available. Includes major reference works and dictionaries. Max Planck researchers who publish a monograph or edited volume with Springer Nature as an Open Access eBook receive a discount on the standard Book Publishing Charge. MPDL covers the costs remaining on a pro rata basis. Further details are available on the MPDL website.

Since the publication of its first installment in 1976 the Theologische Realenzyklopädie has provided a comprehensive account of the state of theological research. Some 2000 articles present a multitude of historical and theological data in their context of faith and thought, theology and religion. A multidisciplinary approach integrates into the theological account not only the disciplines of Old Testament and New Testament Studies, Church History, and Systematic and Practical Theology but also Judaic Studies, Religious Studies and Philosophy.