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. --

SSOAR collects electronic full texts from the domain of the Social Sciences and makes these texts available according to the Berlin Declaration on Open Access to Scientific Knowledge.

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.

zbMATH Open (formerly known as Zentralblatt MATH) is the world's most complete and longest running abstracting and reviewing service in pure and applied mathematics. The MATH Database contains several million entries drawn from more than 3,500 serials and journals, and more than 1,100 book series and monographs. The entries are classified according to the Mathematics Subject Classification Scheme (MSC 2000).