The Primary Sources platform consists of thematic collections of unique materials such as rare books and documents from around the world. These essential research tools in the area of humanities and social sciences are an integrated part of Brill’s product portfolio. Many of the collections are unique, as they are often the only source of rare documents outside of the source library itself. In addition to offering primary source material as collections, Brill also offer groups of collections as series.

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 Komintern segment of the portal contains a complete reference of the inventory of the COMINTERN Archives, and a full text archive of selected documents. Digitized pages cover 59 sub-series concentrating on the commissions, the secretariats and departments that operated under the Executive Committee of the Communist International (ECCI), the country secretariats and regional bureaus, the party delegations with the COMINTERN and other units of special interest such as the Lenin schools, International Workers Relief and the International Federations of Writers and Theatres.

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.

MIA contains the writings of 592 authors representing a complete spectrum of political, philosophical, and scientific thought, generally spanning the past 200 years. Being a communist means working for the self-emancipation of the working class; it means striving to unite the working class, in all its diversity, in the struggle to overthrow capitalism. In the 1840s, Marx and Engels placed communism on a scientific footing through the theory of dialectical materialism. Marxists are those who have continued this ever since. If any one of the following criteria apply, the MIA Collective may decide to place the writer into the Reference Archive: (i) they pre-date Marx and Engels, (ii) they specifically reject Marxism, (iii) their work is practically and theoretically unconnected or hostile toward the workers movement, (iv) their work is idealistic or lacking in dialectic. Where a writer contributes to Marxist theory and practice for a part of their life, while other works lie outside of Marxism, then the whole of their writing will be placed in the Marxist Writers' Archive.Contains: Karl Marx/ Friedrich Engels - Werke ; Rosa Luxenburg; August Bebel; Antonio Gramsci ...

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

The research database "Scholarly Journals and Newspapers in the Age of Enlightenment", conducted by the Göttingen Academy of Sciences, provides an extensive systematic index to German-language periodicals of the 18th century. It is based on the long-term research project "Scholarly Journals and Newspapers", which besides indexing and digitizing these scholarly journals aims to visualize their significant role for the emergence and structures of the "Enlightened scientific community". The project focuses on interdisciplinary journals, comprising of original contributions, book reviews, scholarly news as well as all facets of critique. The interactive online database also includes the data of the two previous research projects "Index of German-language Periodicals" (IdZ 18) and "Systematic Index of German-language Review Journals" (IdRZ 18). By the year 2025, it will give access to 323 periodicals (ca. 2,775 volumes and ca. 1,260,000 pages), spanning the time period 1688-1815.