The Index Theologicus (IxTheo) is an international scientific open access bibliography for theology and religious studies
It covers scientifically relevant information from the Middle Ages to the present day. Publishers are the University Library of Tübingen, the Faculty of Protestant Theology and the Faculty of Roman-Catholic Theology, University of Tübingen.
As of March 2019, IxTheo comprised about 2 million records on theological literature (including monographs and articles), and about 15,000 records are added each year. Subject headings and search capabilities are provided in 9 languages: English, German, French, Italian, Spanish, Portuguese, Greek, Russian and Chinese. A special search capability for specific Bible passages using standard abbreviations is also available.