Periodicals Archive Online is a major archive that makes the backfiles of scholarly periodicals in the arts, humanities and social sciences available electronically, providing access to the searchable full text of hundreds of titles. The database spans more than two centuries of content, 37 key subject areas, and multiple languages.

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.

PLOS (Public Library of Science) is a nonprofit publisher and advocacy organization founded to accelerate progress in science and medicine by leading a transformation in research communication. PLOS entered the publishing arena in October 2003 with the launch of PLOS Biology, followed in October 2004 by PLOS Medicine. Today, it publishes a suite of influential Open Access journals across all areas of science and medicine. The Max Planck Society covers article-processing charges for Max Planck authors centrally. Further details are available on the MPDL website.

Portland Press Limited, the wholly-owned trading subsidiary of the Biochemical Society, is a leading innovative publisher of journals, books and electronic resources. The platform provides Max Planck researchers with selective access to the full texts of journals owned by the Biochemical Society, see link "eJournals licensed" below. The MPG subscription also covers article-processing charges for Max Planck authors in all Portland Press/Biochemical Society journals. Further details are available on the MPDL website.

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.

The Rockefeller University Press publishes three journals with a good standing in the biomedical field: * The Journal of Experimental Medicine, * The Journal of General Physiology, * The Journal of Cell Biology (formerly: The Journal of Biophysical and Biochemical Cytology). The MPG subscription also covers article-processing charges for Max Planck authors in the three journals by RUP. Further details are available on the MPDL website.

The SAO/NASA Astrophysics Data System (ADS) is a digital library portal for researchers in astronomy and physics, operated by the Smithsonian Astrophysical Observatory (SAO) under a NASA grant. The ADS maintains three bibliographic databases containing more than 13 million records covering publications in Astronomy and Astrophysics, Physics, and the arXiv e-prints. Abstracts and full-text of major astronomy and physics publications are indexed and searchable through the new ADS modern search form as well as a classic search form.

SciELO (Scientific Electronic Library Online) is a program of the Sao Paulo Research Foundation for the cooperative publishing of open access journals on the internet. Content includes regional journals from Latin American and the Caribbean as well as titles from Spain, Portugal and South Africa. The index covers approximately 650 titles (over 350 adding content to journals already covered in the Web of Science) and contains several million cited references.

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.

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.

Springer Nature publishes the largest available collection of reproducible laboratory protocols and methods for the life sciences. The Experiments platform provides accees to the content from SpringerProtocols, Nature Methods, Nature Protocols and Protocol Exchange through a single easy-to-use platform, designed to save researchers' time.

The Arabidopsis Information Resource (TAIR) maintains a database of genetic and molecular biology data for the model higher plant Arabidopsis thaliana. Data available from TAIR includes the complete genome sequence along with gene structure, gene product information, gene expression, DNA and seed stocks, genome maps, genetic and physical markers, publications, and information about the Arabidopsis research community. Gene product function data is updated every week from the latest published research literature and community data submissions. TAIR also provides extensive linkouts from our data pages to other Arabidopsis resources. The Arabidopsis Biological Resource Center at The Ohio State University collects, reproduces, preserves and distributes seed and DNA resources of Arabidopsis thaliana and related species. Stock information and ordering for the ABRC are fully integrated into TAIR.

The vifabio portal offers rapid access to biological literature and information. It offers a parallel search in various biologically relevant library catalogues, bibliographic databases, and the internet guide (a collection of selected, quality controlled internet sources).

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.

Wiley Current Protocols contains a collection of updatable step-by-step, reproducible laboratory methods, covering a total of 20,000 protocols across 18 subjects in the life sciences. Each protocol is carefully selected by the editorial board members, written by experts, and rigorously edited to ensure repeated success.

The World Christian Database (WCD) provides comprehensive statistical information on world religions, Christian denominations, and people groups. Extensive data are available on 9,000 Christian denominations, 13,000 ethnolinguistic peoples, as well as data on 5,000 cities, 3,000 provinces and 234 countries.

The World Religion Database (WRD) contains detailed statistics on religious affiliation for every country of the world. It provides source material, including censuses and surveys, as well as best estimates for every religion to offer a definitive picture of international religious demography. It offers best estimates at multiple dates for each of the world’s religions for the period 1900 to 2050.

Zoological Record provides access to publications in animal biology and biodiversity. It covers 5,000 serials, plus many other sources of information, including books, reports, and meetings. It contains, in particular, a significant amount of literature on insects, reptiles, birds, fish and wildlife which is not included elsewhere (e.g. in BIOSIS Previews). It is also a leading taxonomic reference work.