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.

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").

Die Bibliographie des Musikschrifttums online ist eine internationale, interaktive und frei nutzbare Bibliographie für die Musikwissenschaft. Sie dient als Fortsetzung des bis zum Berichtsjahr 1988 gedruckt erschienenen Werkes.

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.

Education Systems International is an Internet guide on education systems worldwide. The database offers links to institutions, databases, full texts and collections of facts from more than 230 countries and regions, which are of interest for users who work in educational research and administration. -- BildungsSysteme International als "Subject Internet Guide" des DIPF bietet Links zu Bildungsministerien, Bildungseinrichtungen, Fachgesellschaften, nationalen und internationalen Organisationen, zu Datenbanken, Volltexten und Fakteninformationen gegenwärtig aus mehr als 230 Ländern und Regionen.

Each of the 371 databases of BioCyc describes the genome and metabolic pathways of a single organism. The BioCyc databases are divided into 3 tiers, based on their quality: Tier 1: 3 Databases, which have been created through intensive manual efforts and receive continuous updating: 1) *EcoCyc* describes the model organism Escherichia coli K-12. 2) *MetaCyc* describes metabolic pathways and enzymes for more than 1,500 organisms. 3) *BOCD* (BioCyc Open Compounds Database) is an open collection of chemical compound data from the BioCyc databases. BOCD includes metabolites, enzyme activators, inhibitors, and cofactors. Tier 2: 20 Databases, which were computationally generated and have undergone moderate curation. Tier 3: 349 Databases, which were also computationally generated, but have undergone no curation. Scientists can use the BioCyc Web site to visualize individual metabolic pathways or to view the complete metabolic map of an organism. The latter diagram can be used to analyze gene expression, proteomics, or metabolomics data, such as to produce animated views of time-course gene-expression experiments. The BioCyc Web site also provides genome browsing capabilities, and for the *EcoCyc* databases in particular, provides extensive information about transcriptional mechanisms of gene regulation.

A 100 million word collection of samples of written and spoken language from a wide range of sources, designed to represent a wide cross-section of current British English, both spoken and written.

The Center for Research Libraries (CRL) is an international consortium of university, college, and independent research libraries. Founded in 1949, CRL supports advanced research and teaching in the humanities, sciences, and social sciences by preserving and making available to scholars the primary source material critical to those disciplines. CRL acquires and preserves newspapers, journals, documents, archives, and other traditional and digital resources from a global network of sources. Most materials acquired are from outside the United States, and many are difficult to obtain or at-risk materials from six major world regions: Africa, the Middle East, Slavic and Eastern Europe, Southeast Asia, South Asia, and Latin America.

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.

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).

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.

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.

The Deposit Once of the Technische Universität Berlin makes qualified scientific text documents and research data of members of the TU Berlin available online. The repository is committed to the principles of Open Access and includes parallel publications from peer-reviewed publishers (post-prints) as well as dissertations, monographs, conference proceedings, collections and other scientific treatises.

The Digital Library of the Commons (DLC) is a gateway to the international literature on the commons. The DLC provides free and open access to full-text articles, papers, and dissertations. This site contains an author-submission portal; an Image Database; the Comprehensive Bibliography of the Commons; a Keyword Thesaurus, and links to relevant reference sources on the study of the commons.

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.

The ECOLEX database includes information on treaties, international soft-law and other non-binding policy and technical guidance documents, national legislation, judicial decisions, and law and policy literature. Users have direct access to the abstracts and indexing information about each document, as well as to the full text of most of the information provided.