BASE is a multidisciplinary search engine for scholarly internet resources which have been harvested from several hundred scientific repositories. Some of the indexed resources in BASE are subject to license, while most material is free available ("open access").

The Staatsbibliothek zu Berlin - Preußischer Kulturbesitz (Berlin State Library - Prussian Cultural Heritage) acquires texts from all fields of knowledge in all languages, in every available form, from all epochs and all countries of the world - providing the materials are of interest for academic and research purposes. Current holdings and collections include printed works from many centuries, manuscripts, music autographs, maps, globes, atlases, newspapers and periodicals, various microformed materials, an increasing number of digitally presented texts as well as extensive databases.

The Bibliography of the History of Art (BHA) contains abstracts and indexes of current publications in the history of art, including scholarly journals, conferences, book, exhibition reviews, and exhibition catalogues. The records consist of bibliographic citations, abstracts, and indexing. Note that the database search includes BHA, covering 1990-2007, the International Bibliography of Art (IBA), covering the years 2008 and part of 2009, and the Répertoire de la litterature de l'art (RILA), one of the predecessors of BHA, with records that cover 1975–1989.

BN-OPALE PLUS combines into one catalog the records for the printed, sound, audiovisual, and multimedia materials collected by the Bibliothèque nationale de France (BnF) from its beginnings to the present day. The BN-OPALE PLUS catalog contains records for: * Books and periodicals making up the heritage collections, stored in BnF's François-Mitterrand Library, * Microfiche and microfilm, mostly created from heritage materials, * A selection of books and periodicals from special departments, * Open-Access materials from all the BnF libraries, * Sound recordings, videos, multimedia, and electronic materials comprising the heritage collections * Printed material and periodicals digitized by BnF, mostly in image format, * Electronic periodicals of which BnF also has the printed version, * Still images digitized by BnF, * Special materials regarding performing arts (pamphlets, programs, manuscripts,...) and cinema (movie posters, photographs). In addition, this catalog offers authority records containing extensive information on access rights (intellectual property rights and copyrights, subject matter, certificates, brand names, and others).

CiteSeer is a scientific literature digital library and search engine that focuses primarily on the literature in computer and information science. CiteSeer aims to improve the dissemination and feedback of the scientific literature and to provide improvements in functionality, usability, availability, cost, comprehensiveness, efficiency, and timeliness in the access of scientific and scholarly knowledge.

Copac exposes rare and unique research material by bringing together the catalogues of c.90 major UK and Irish libraries. In a single search you can discover the holdings of the UK’s national libraries (including the British Library), many University libraries, and specialist research libraries.

CORE’s mission is to aggregate all open access research outputs from repositories and journals worldwide and make them available to the public. In this way CORE facilitates free unrestricted access to research for all. We offer seamless access to millions of open access research papers, enrich the collected data for text-mining and provide unique services to the research community. CORE is providing a free API.

Data Europa EU is a central point of access to European open data from international, European Union, national, regional, local and geodata portals. The official portal for Euopean data consolidates the former EU Open Data Portal and the European Data Portal. Data Europa EU gives access and fosters the reuse of European open data among citizens, business and organisations. The portal promotes and supports the release of more and better-quality metadata and data by the EU’s institutions, agencies and other bodies, and European countries, enhancing the transparency of European administrations. Furthermore, it is intended to educate citizens and organisations about the opportunities that arise from the availability of open data. Currently, Data Europa EU contains more than 1.5 million European public sector datasets grouped by over 180 catalogues and pertaining to different topical categories.

The catalog comprises the holdings of the locations Leipzig since 1913, Frankfurt am Main since 1945, the holdings of the Deutsches Musikarchiv since 1976, and archival papers of the Deutsches Exilarchiv 1933-1945 since 2005. The catalog covers monographs, journals, maps and atlases, music and sound storage media, and dissertations published in Germany since 1913 (in print or electronically), in addition, translations from German into other languages and foreign-language works related to Germanic culture (since 1941). -- Der Katalog umfasst die Bestände der Standorte Leipzig seit 1913, Frankfurt am Main seit 1945, die Bestände des Deutschen Musikarchivs seit 1976 und die Archivalien des Deutschen Exilarchivs 1933-1945 seit 2005. Der Katalog beinhaltet in Deutschland seit 1913 erschienene Monografien, Zeitschriften, Karten und Atlanten, Musikalien und Tonträger, Dissertationen und Habilitationsschriften in gedruckter oder elektronischer Form, außerdem Übersetzungen aus dem Deutschen in andere Sprachen und fremdsprachige Germanica (seit 1941).

Dimensions is a linked research knowledge system that re-imagines discovery and access to research. Developed by Digital Science in collaboration with over 100 leading research organizations around the world, Dimensions brings together grants, publications, citations, alternative metrics, clinical trials, patents and policy documents to deliver a platform that enables users to find and access the most relevant information faster, analyze the academic and broader outcomes of research, and gather insights to inform future strategy.

GBV is the Common Library Network of the German Federal States Bremen, Hamburg, Mecklenburg-Vorpommern, Niedersachsen, Sachsen-Anhalt, Schleswig-Holstein and Thüringen. The head office of the GBV (VZG) is situated in Göttingen. The GBV has established a virtual library in form of the GBV Union Catalogue (GVK) combining the resources of all participating libraries and making them easily accessible to the public.

GeoReM is a Max Planck Institute database for reference materials of geological and environmental interest, such as rock powders, synthetic and natural glasses as well as mineral, isotopic, biological, river water and seawater reference materials. It contains published analytical data and compilation values (major and trace element concentrations and mass fractions, radiogenic and stable isotope ratios). GeoReM covers all important metadata about the analytical values such as uncertainty, analytical method and laboratory. Sample information and references are also included. GeoReM contains almost 3,400 reference materials, about 46,200 analyses from almost 10,000 papers, and preferred analytical values (State: November 2017).

The database GEOROC is maintained by the Geoscience Centre at Göttingen University. The database is a comprehensive collection of published analyses of volcanic rocks and mantle xenoliths. It contains major and trace element concentrations, radiogenic and nonradiogenic isotope ratios as well as analytical ages for whole rocks, glasses, minerals and inclusions. Samples come from 11 different geological settings. Metadata include, among others, geographic location with latitude and longitude, rock class and rock type, alteration grade, analytical method, laboratory, reference materials and references.

The GESIS search can be used to find information about social science research data and open access publications. It covers: * Research Data * Variables from questionnaires * Instruments and tools * Literature, incl. publications on research data & surveying instruments, open access publications in the social sciences, as well as literature on the topic "Women in science" * Collections of the GESIS library * GESIS webpages, incl. general information and offers on the GESIS websites

H1 Connect is a literature awareness and recommendation tool that comprehensively highlights and reviews the most interesting papers published in biology and medicine. It is based on the recommendations of a faculty of selected leading scientists and enables researchers to set up a personalized literature service.

The union catalog lists the holdings of all scientific libraries in Hessen and Rheinhessen. Inter-library loan requests may be submitted.

The International Monetary Fund's eLibrary simplifies analysis and research with direct access to the IMF's periodicals, books, working papers and studies. Various statistical and visualization tools to showcase IMF datasets are offered free of charge via the IMF Data platform.

The Internet Archive is a non-profit organization that offers permanent access for the general public to historical collections that exist in digital format. The Internet Archive includes collections of digitized materials, including websites, software applications and games, music, movies and videos, moving images, and nearly three million public-domain books. The Internet Archive allows the public to upload and download digital material , but most of its data is collected automatically by its web crawlers to preserve as much of the public web as possible. The Wayback Machine, a huge web archive, contains over 150 billion web captures.

This database covers international publications about German history from the early days until the present. Die Datenbank erfaßt und erschließt internationale Veröffentlichungen zur deutschen Geschichte von den Anfängen bis zur Gegenwart.