The index to volumes 1-20 of the Nietzsche Studien contains a list of the papers published from 1972 to 1991. Its core is an index of keywords which enables researchers to gain rapid access to the texts of particular interest to them and thus to make more efficient use of the yearbook. For the keyword listing, the compilers have set up an index of thematic groupings by which the thematic foci of the papers are arranged. An indispensable search tool is provided by the keyword indexes, which access the papers, central terms, names and the works used, and thus enable researchers successfully to conduct searches by topic. A further tool giving insight into the development of Nietzsche research is provided by an index of personal names and a cumulative bibliography of the secondary literature used in the papers.