The database Music Online Reference of Alexander Street Press comprises four parts * Classical Scores Library, Volume I - collection of musical prints, manuscripts and up to now unpublished material from the 15th to the 20th century. Please note that Boosey & Hawkes Scores are not included. * Classical Music Reference Library - collection of relevant reference works of approx. 55,000 pages about the history of western classical music from the Middle Ages to the 21st century. * African American Reference Library - comprehensive reference work and collection of rare and up to now unpublished materials about the history of Afro-American music from the beginnings until the 1970s, with a complete coverage of more than 45,000 pages. * The Garland Encyclopedia of World Music Online - comprehensive standard reference work with more than 1,200 elaborate articles about subjects or persons, and approx. 9,200 pages about traditional ethno music worldwide, edited by James Porter and Timothy Rice.

The two databases (which are searchable simultaneously) contain Sigrid Krämer's collections about more than 34.000 writers and more than 16.000 owners of medieval manuscripts. Along with their names, personal data (if known), manuscript references and criticism are included. The database, which has never been published in print, is relevant for all disciplines (especially those with a focus on medieval studies) that deal with written tradition.

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.

Based on the digitization of K. G. Saur's Biographical Archives, WBIS Online provides biographical information on over 6 Million people from the 8th century B.C. to the present as well as from all countries and regions worldwide. The subscription covers all biographical archives, except the German Biographical Archive, DBA.