The OSF Preprints search combines records from various preprint repositories, including arXiv, bioRxiv, Cogprints, PeerJ, PsyArXiv, RePEc and SocArXiv.

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.

Various dictionaries are available.

The PrimateLit database provides bibliographic access to the scientific literature on nonhuman primates for the research and educational communities. Coverage of the database includes all publication categories (articles, books, abstracts, technical reports, dissertations, book chapters, etc.) and many subject areas (behavior, colony management, ecology, reproduction, field studies, disease models, veterinary science, psychology, physiology, pharmacology, evolution, taxonomy, developmental and molecular biology, genetics and zoogeography).

Project Gutenberg is a volunteer effort to digitize and archive cultural works. Founded in 1971 by Michael Hart, it is the oldest digital library. Project Gutenberg's mission is "To encourage the creation and distribution of eBooks".

A digital archive of life sciences journal literature managed by the National Center for Biotechnology Information (NCBI) at the U.S. National Library of Medicine (NLM).

Refubium is a service of the university library of the Freie Universität Berlin. As an institutional repository it collects documents, dissertations, postdoctoral theses, and research data.

MPG Resource Navigator is a web application to navigate through scientific information resources available to staff and guests of the Max Planck Society. It includes licensed databases, digital collections, and reference works. In addition, recommendable retrieval tools available on the web free of charge are part of the collection. Moreover, almost all Max Planck Institute library catalogs, as well as selected external ones, are accessible from here.

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.

SocArXiv, open archive of the social sciences, provides a free, non-profit, open access platform for social scientists to upload working papers, preprints, and published papers, with the option to link data and code. SocArXiv is dedicated to opening up social science, to reach more people more effectively, to improve research, and build the future of scholarly communication.

SocioHub – ist das Portal des Fachinformationsdienstes Soziologie – es dient als zentrale Anlaufstelle für Ihre Literatursuche, Kommunikation und Information. Anstatt mehrere Webseiten besuchen zu müssen befinden sich hier alle Bereiche auf einer Plattform – direkt auf die Bedürfnisse der Soziologie zugeschnitten.

The German Socio-Economic Panel (SOEP) is a wide-ranging representative longitudinal study of private households, located at the German Institute for Economic Research, DIW Berlin. Every year, there were nearly 11,000 households, and about 30,000 persons sampled by the fieldwork organization Kantar Public Germany. The data provide information on all household members, consisting of Germans living in the Old and New German States, Foreigners, and recent Immigrants to Germany. The Panel was started in 1984. Some of the many topics include household composition, occupational biographies, employment, earnings, health and satisfaction indicators.

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.

SSOAR collects electronic full texts from the domain of the Social Sciences and makes these texts available according to the Berlin Declaration on Open Access to Scientific Knowledge.

The SSRN eLibrary consists of two parts: an Abstract Database containing abstracts on over 60,500 scholarly working papers and forthcoming papers and an Electronic Paper Collection currently containing over 38,400 downloadable fulltext documents in Adobe Acrobat pdf format. The eLibrary also includes the research papers of a number of Fee Based Partner Publications.

The department "Survey Data Curation", part of GESIS - Leibniz Institute for the Social Sciences, processes and prepares social science research data across a diverse range of data types to support research, especially in comparative perspectives across space and time. The curated data include long-term national (e.g., ALLBUS, GLES, Politbarometer, FReDA) and international (e.g., ISSP, EVS, CSES, Eurobarometer) survey programs with large user communities. The data are prepared for immediate re-use for research and teaching purposes. The department also offers services for linking surveys with geo-data and digital behavioral data.

The BSZ develops and maintains the SWB database in cooperation with 1,200 libraries in Baden-Württemberg, Pfalz, Saarland and Sachsen. The online catalog offers bibliographic data free of charge: Monographs, periodicals, articles, loose-leaf collections, off-prints, conference proceedings, university publications, reviews, abstracts, tables of contents, maps, music, audiovisual material, microforms, electronic resources (data media), online resources; scientific and popular literature from all subjects and in all languages from the 15th century to the present; scientific literature (according to the DFG special subject fields programme) from theology, ancient orient, art, music, archeology, law and criminology;

EVIFA, the portal of Social and Cultural Anthropology, offers anthropological and folkloristic information from one source. It gives a fast, comprehensive access to specific information for anthropological research, regardless of the where about.

The World Bank is the largest single source of development knowledge. The World Bank Open Knowledge Repository (OKR) is The World Bank’s official open access repository for its research outputs and knowledge products. Through the OKR, the World Bank collects, disseminates, and permanently preserves its intellectual output in digital form. The OKR also increases the range of people who can discover and access Bank content - from governments and civil society organizations (CSOs), to students and the general public. The OKR is built on DSpace and is interoperable with other repositories. It supports optimal discoverability and reusability of the content by complying with Dublin Core Metadata Initiative (DCMI) standards. All OKR metadata is exposed through the Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH) protocol. By extending and improving access to World Bank research, the World Bank aims to encourage innovation and allow anyone in the world to use Bank knowledge to help improve the lives of those living in poverty.

You can search for popular books, music CDs and videos—all of the physical items you're used to getting from libraries. You can also discover many new kinds of digital content, such as downloadable audiobooks. You may also find article citations with links to their full text; authoritative research materials, such as documents and photos of local or historic significance; and digital versions of rare items that aren't available to the public.