1. A Theory of Indexing: Indexing Theory as a Model for Information Storage and Retrieval;Landry,1971
2. The Descriptive Continuum, a “Generalized” Theory of Indexing;Jonker,1957
3. Indexing Theory, Indexing Methods and Search Devices;Jonker,1964
4. Mathematical Model of Indexing;Heilprin,1957
5. A Theory of Indexing;Salton,1975