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.

With more than 700.000 items, the BBF is today Europe's second largest library specialised in education. Like the Herzog-August-Bibliothek in Wolfenbüttel, it belongs to the association of German cultural research libraries fulfilling a national role.

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.

The search engine provides users with the option to search various historically relevant databases and catalogues on general and European history in parallel.

Das Projekt "Propylaeum – Virtuelle Fachbibliothek Altertumswissenschaften" ist ein Internetportal, das Fachinformationen für den gesamten Bereich der Altertumswissenschaft anbietet, derzeit für die Fächer Ägyptologie, Alte Geschichte, Klassische Archäologie, Klassische Philologie und Vor- und Frühgeschichte. --

The German National Library of Science and Technology (TIB) ‒ Leibniz Information Centre for Science and Technology and University Library is a central specialised library, responsible for operating the German National Library for technology, architecture, chemistry, information technology, mathematics and physics as well as the University Library for Leibniz Universität Hannover. As the world's largest specialised library in its fields, the library has excellent collections of technical and scientific specialist and research information.

Zenodo is an open data repository, developed and operated by CERN. It is an catch-all repository, that welcomes research from all over the world, and from every discipline. Zenodo does not impose any requirements on format, size, access restrictions or licence. A digital object identifier (DOI) is automatically assigned to all Zenodo files and it is integrated into reporting for research funded by the European Commission.