Since the publication of its first installment in 1976 the Theologische Realenzyklopädie has provided a comprehensive account of the state of theological research. Some 2000 articles present a multitude of historical and theological data in their context of faith and thought, theology and religion. A multidisciplinary approach integrates into the theological account not only the disciplines of Old Testament and New Testament Studies, Church History, and Systematic and Practical Theology but also Judaic Studies, Religious Studies and Philosophy.

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.

Casalini libri's full text platform offers access to over 29,000 ebooks and 840 ejournals from more than 200 Italian, Spanish, French and Portuguese publishers. Max Planck users have access to: * EIO Monographs - a collection of 1,500 monographs and proceedings in humanities and social sciences from academic publishers in Italy. * EIO Periodicals Archive - pre-2011 content of 221 academic journals published by various Italian publishers.

Archive of 15 periodicals and proceedings published online by Trans Tech Publications during the period between 1984 and 2022. The archive - with its broad subject diversity and its renowned journals indexed in well-established databases (e.g. Material Science Forum, Defect and Diffusion Forum, Key Engineering Materials) - is a valuable platform for the bibliographic retrieval of scientists, especially in the field of modern solid state and materials science.

The Umwelt-Online platform contains all relevant legal regulations on topics such as environmental protection, occupational safety, transport of dangerous goods, hazardous materials and systems engineering. The content is continuously updated. Die Plattform Umwelt-Online enthält alle relevanten rechtlichen Regelungen zu den Themen Umweltschutz, Arbeitssicherheit, Gefahrguttransporte, Gefahrstoffe, Anlagentechnik und Anlagensicherheit. Die Inhalte werden kontinuierlich entsprechend den Veröffentlichungen der Regelungsgeber aktualisiert.

Universitetskaja Biblioteka Online offers ebooks on Russian Literature and Linguistics, History, Law, Economics, Social Sciences and Culture as well as Russian, Eurasian and Slavic Studies. The ebooks are hosted on University Library Online, e-content platform with English language interface. Additionally, for gaining a deeper understanding of Russia and Russian language, it provides access to: encyclopedias, audiobooks and maps.

Ut per litteras apostolicas provides a complete collection of papal letters from the 13th and 14th centuries. The database represents an electronic version of the renowned * Registres et lettres des Papes du XIIIe siècle (32 vols.; Rome, 1883- ) * Registres et lettres des Papes du XIVe siècle (48 vols.; Rome, 1899- ) It is an invaluable source regarding various aspects of medieval history and society.

The World Christian Database (WCD) provides comprehensive statistical information on world religions, Christian denominations, and people groups. Extensive data are available on 9,000 Christian denominations, 13,000 ethnolinguistic peoples, as well as data on 5,000 cities, 3,000 provinces and 234 countries.

The World Religion Database (WRD) contains detailed statistics on religious affiliation for every country of the world. It provides source material, including censuses and surveys, as well as best estimates for every religion to offer a definitive picture of international religious demography. It offers best estimates at multiple dates for each of the world’s religions for the period 1900 to 2050.

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.

Zoological Record provides access to publications in animal biology and biodiversity. It covers 5,000 serials, plus many other sources of information, including books, reports, and meetings. It contains, in particular, a significant amount of literature on insects, reptiles, birds, fish and wildlife which is not included elsewhere (e.g. in BIOSIS Previews). It is also a leading taxonomic reference work.