arXiv is an e-print service in the fields of physics, mathematics, computer science, quantitative biology, quantitative finance, statistics, electrical engineering and systems science, and economics. It provides access to more the 1.3 million e-prints. The Max Planck Society is a member institution of arXiv.

CESSDA provides large scale, integrated and sustainable data services to the social sciences, having evolved from a network of European data service providers into a legal entity and large-scale infrastructure under the auspices of the European Strategy Forum on Research Infrastructures (ESFRI) Roadmap.CESSDA provides a seamless interface to datasets from social science data archives across Europe.

Clio-online is a central Internet gateway for historical scholarship in teaching and research. Sponsored by the Deutsche Forschungsgemeinschaft (DFG), the gateway enables efficient access to the diverse range of historical online ressources available to scholars and teachers within the field of history. Clio-online ist ein zentrales Internet Fachportal zur Geschichte. Seit Mai 2002 von der Deutschen Forschungsgemeinschaft gefördert, ermöglicht das Projekt durch seine Online-Dienste und Service-Angebote einen effizienten Zugang zu den umfangreichen Online-Ressourcen innerhalb der Geschichtswissenschaften.

Welcome to CogPrints, an electronic archive for self-archive papers in any area of Psychology, neuroscience, and Linguistics, and many areas of Computer Science (e.g., artificial intelligence, robotics, vision, learning, speech, neural networks), Philosophy (e.g., mind, language, knowledge, science, logic), Biology (e.g., ethology, behavioral ecology, sociobiology, behaviour genetics, evolutionary theory), Medicine (e.g., Psychiatry, Neurology, human genetics, Imaging), Anthropology (e.g., primatology, cognitive ethnology, archeology, paleontology), as well as any other portions of the physical, social and mathematical sciences that are pertinent to the study of cognition.

The DBLP server provides bibliographic information on major computer science journals and proceedings. Initially the server was focused on DataBase systems and Logic Programming (DBLP), now it is gradually being expanded toward other fields of computer science. You may now read "DBLP" as "Digital Bibliography & Library Project". The server indexes more than 380000 articles and contains several thousand links to home pages of computer scientists (May 2003).

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.

DART-Europe is a partnership of research libraries and library consortia who are working together to improve global access to European research theses. The Dart-Europe E-theses Portal enables access to open access research theses from nearly 600 universities in 28 European countries.

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.

"Data Services for the Social Sciences" is a department of GESIS - Leibniz Institute for the Social Sciences. Its mission is to foster FAIR data, open science and reproducible research in the quantitative and computational social sciences. To ensure that data holdings remain usable and interpretable over the long term, it offers sustainable infrastructures and services for data management, curation, and long-term preservation. ​These include archiving services with different curation levels for different needs as well as access to archived data including access to sensitive data in the GESIS Secure Data Center. The services also cover the data registration agency da|ra and training on data management for easier retrieval and re-analysis of data.

DBIS (Datenbank-Infosystem) is a web application to find scientific databases. It includes licenced and free databases for most disciplines.

DEPATISnet is a service provided to you by the German Patent and Trade Mark Office. You can conduct online searches in patent publications from around the world stored in the database of DEPATIS, the in-house patent information system of the GPTO.

Digi20 concentrates on the digitalization of monographs published in the second half of the 20th century, predominantly in the field of humanities and social sciences. In the first phase of the project, approx. 4,700 titles of programme segments of the publishers Vandenhoeck & Ruprecht, Wilhelm Fink / Ferdinand Schöningh as well as Otto Sagner were digitized. In a second phase, further approx. 1,750 titles are being included till 2014 by consecutively digitizing all monographs up to a defined ‘Moving Wall’ of three to five years to the current year of publication.

Since its foundation in 1964 the Max Planck Institute for European Legal History has been intensively engaged in research into the history of private law in Europe. It therefore has a particularly rich store of literary sources on 19th century German, Austrian and Swiss private and civil procedural law. With support from the German Research Foundation (DFG) it has been possible to digitize this exceptional concentration of material and make it available to a wider scientific audience. In the course of the project, which extended from 1997 until 2002, some 4,316 volumes were digitized comprising around 1,350,000 pages. For the Institute library this venture into digitization represents a continuation of its long-standing initiative to maintain and conserve its collections.

The primary aim of DOAB is to increase discoverability of Open Access books. Academic publishers are invited to provide metadata of their Open Access books to DOAB. An overview of participating publisher can be found here.

EconBiz - a suject portal for economics and business studies - supports you in retrieving economic literature. It offers a literature search across important German and international databases, including the holdings of ZBW, and provides access to information services of libraries. EconBiz - die Virtuelle Fachbibliothek Wirtschaftswissenschaften - unterstützt Sie bei der Recherche wirtschaftswissenschaftlicher Fachinformationen. Sie können in Internetquellen, in Online-Katalogen und Volltexten recherchieren und auf Informationsdienstleistungen von Bibliotheken zugreifen. Enthält neben aktueller Literatur viele Publikationen , die für Wirtschaftshistoriker interessant sind (1500 ff).

The Library of Economics and Liberty is dedicated to advancing the study of economics, markets, and liberty. The books and essays on this website represent classics of economic thought, both historical and modern.•Authoritative editions of classics in economics, and related works in history, political theory and philosophy. Contains also blogs, talks and essays.The Library of Economics and Liberty carries the popular Concise Encyclopedia of Economics, edited by David R. Henderson.

EconStor is the Open Access server of the German National Library of Economics, Leibniz Information Centre for Economics. EconStor provides a basis for the free publication of academic literature in economics.

Edition Open Access provides open access to the publications of the Max Planck Research Library for the History and Development of Knowledge. The aim is to disseminate the results of scholarly work – in accordance with the open-access paradigm – to a broad audience rapidly and at low cost. The volumes presented here are directed at scholars and students in a wide range of disciplines. The works are available online both as print-on-demand books and open-access publications and can be accessed, together with additional information.

Throughout Europe, national patent offices and the European Patent Office (EPO) offer free patent information on the Internet Patents reveal solutions to technical problems, and they represent an inexhaustable source of information: more than 80 percent of man's technical knowledge is described in patent literature. From the middle of 1998 onwards, esp@cenet users have been able to access the bibliographic data of all patents published in the preceding two years by any member state of the European Patent Organisation, as well as by the European Patent Office and the World Intellectual Property Organization (WIPO). In addition, full-page facsimile images of documents are also retrievable to facilitate more detailed analysis of these documents. The data for this particular service is stored at the relevant national office.