Selected references
- Harold Borko and Myrna Bernick. Automatic document classification part II. additional experiments. Journal of the ACM, 11(2):138-151, April 1964.
- M. E. Maron. Automatic indexing: An experimental inquiry. Journal of the ACM, 8(3):404-417, July 1961.
- John O'Connor. Mechanized indexing methods and their testing. Journal of the ACM, 11(4):437-449, October 1964.
- H. Edmund Stiles. The association factor in information retrieval. Journal of the ACM, 8(2):271-279, April 1961.