This historic journal index enables the simultaneous search in millions of citations for articles published in the arts, humanities and social sciences, across more than 300 years. It enables researchers quickly and comprehensively to identify articles relevant to their field of study and reduces what could take years of research to a matter of minutes. Journals indexed span 37 key subject areas and multiple languages.

Project Euclid's mission is to advance scholarly communication in the field of theoretical and applied mathematics and statistics. The MPG licensed the EUCLID PRIME collection, a growing aggregation of well-cited, peer-reviewed journals in mathematics and statistics. Additional publications are available on an Open Access basis.

Project MUSE is a leading provider of digital humanities and social science content for the scholarly community. Since 1995 the MUSE journal collections cover full-text versions of scholarly journals from many of the world's leading university presses and scholarly societies, with over 120 publishers currently participating.

PsycARTICLES comprises journals published by the American Psychological Association, the APA Educational Publishing Foundation, the Canadian Psychological Association, and Hogrefe Publishing Group, from 1894 onwards.

The PsycINFO databases cover the professional and academic literature in psychology and related disciplines including medicine, psychiatry, nursing, sociology, education, pharmacology, physiology, linguistics, and other areas. Coverage is worldwide, and includes references and abstracts to over 1300 journals and to dissertations in more than 30 languages, and to book chapters and books in the English language. Over 50,000 references are added annually. Popular literature is excluded.

The PsyJOURNALS collection is a diverse portfolio of highly-regarded, peer-reviewed journals in German and English languages published by Hogrefe and by Hans Huber that cover a wide range of areas within psychology and psychiatry. Max Planck researchers have full text access to 31 journals from 2015 onwards, with a two-year moving wall.

"Psyndex - Literature & Audiovisual Media" contains records on psychology from researchers in Germany, Austria, and Switzerland. Compiled by the German Center for Documentation and Information in Psychology at the University of Trier (ZPID), this database covers German and English journal articles, books, chapters, reports, dissertations as well as audiovisual media. The database is bilingual: titles and descriptors are in German and English. German publications are abstracted in German; English publications in English. The database is indexed with the Thesaurus of Psychological Index Terms by permission of the American Psychological Association. A bilingual thesaurus is included with the database.

"Psyndex - Tests" contains records on psychology from researchers in Germany, Austria, and Switzerland. Compiled by the Leibniz Institute for Psychology Information (ZPID), this database covers about 5,000 extensive descriptions of psychological and educational tests used in the German-speaking countries. "Psyndex - Tests" is bilingual: titles and descriptors are in German and English. German publications are abstracted in German; English publications in English. The database also include theoretical background, testing procedures, test construction, reliability, validity, fields of application, research and other selected literature, a comprehensive discussion, and test reviews. "Psyndex - Tests" is indexed with the Thesaurus of Psychological Index Terms by permission of the American Psychological Association (APA). A bilingual thesaurus is included with the database.

SAGE Journals Online provides access to more than 1000 journals with a coverage spanning the humanities, social sciences, and science, technology, and medicine. Max Planck researchers have full text access to a multidisciplinary selection of the full journal collection. In addition, the agreement covers article-processing charges for Max Planck authors in Gold Open Access journals and in hybrid titles in the SAGE Premier package. Further details are available on the MPDL website.

ScienceOpen is a networking platform for scholars to enhance their research in the open, make an impact, and receive credit for it. The site provides advanced search and discovery functions, combined with post-publication peer review, recommendation, social sharing, and collection-building features. The Max Planck Society covers article-processing charges for ScienceOpen Research and ScienceOpen Poster centrally. Further details are available on the MPDL website.

The service "SIAM Journals Online" (SJO) provides access to the full texts of the 14 SIAM journals and to a database covering these journals.

Archive of "SIAM Journals Online" covering 17 journals.

SocINDEX is the world's most comprehensive and highest quality sociology research database. Subject headings from a 15,000 term sociology-specific thesaurus designed by expert lexicographers and extensive indexing for books, monographs, conference papers and other sources is included. Searchable cited references are also provided.

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.

The journal collection on the SpringerLink platform includes more than 2,500 English-language and close to 200 German-language journals. The current subscription provides Max Planck researchers with full text access to nearly the entire journal collection. In addition, the Max Planck Society covers article-processing charges in line with the SpringerOpen and the Springer Open Choice programmes. Further details are available on the MPDL website.

The Subject Gatewy for Law is an instrument for the legal information retrieval. It provides straightforward access to legal information in the Internet. Die Virtuelle Fachbibliothek Recht ist ein Instrument für die rechtswissenschaftliche Online-Recherche. Sie bietet einen ortsunabhängigen und unkomplizierten Zugang zu rechtswissenschaftlichen Fachinformationen im Internet.

zbMATH Open (formerly known as Zentralblatt MATH) is the world's most complete and longest running abstracting and reviewing service in pure and applied mathematics. The MATH Database contains several million entries drawn from more than 3,500 serials and journals, and more than 1,100 book series and monographs. The entries are classified according to the Mathematics Subject Classification Scheme (MSC 2000).