1. Function of indexing and its historical role;Roy,1998
2. Physical Bibliography for Librarians, second ed.;Ranganathan,1974
3. The Art of Indexing of Books and Periodicals;Knight,1979
4. British Standards Institution. Recommendation for the preparation of indexes for books, periodicals and other publications (B. S. 370:1954). London, 1964. p. 6.
5. Handbook of Information Systems and Services;Atherton,1977