1Luhn, H. P.: The IBM Electronic Information Searching System, IBM Rescarch Center, Yorktown Heights, New York, May 1952, 18.
2Luhn, H. P.: The Automatic Creation of Literature Abstracts (Auto-Abstracts)9 IBM Iournal of Research and Development, 1958, 2(2), 159-165.
3Borko, H.: Automated Language Processing, New York, John Wiley & Sons, 1967, 128.
4Baxendale, P. E.: Machinc-made Index for Technical Literature-An Experiment, IBM Journal of Research and Development,1958, 2(4), 354-361.
5Oswald, V. A., Wyllys, R. E. et al: Automatic Indexing and Abstracting of the Contents of Documents, Planning Research Corporation, Los Angeles, California, 1959, AD 231606.
6Edmundson, H. P.: New Methods in Automatic Extracting, Journal of the Association for Computing Machinery, 1969, 16(2), 264-285.
7Edmundson, H. P.: Final Report on the Study for Automatic Abstracting, Thompson Ramo Wooldridge, Ine, California, 1961, PB 166532.
8Earl, L. L.: Experimcnts in Automatic Extracting and Indexing, Information Storage & Retrieval, 1970, 6(4), 313-314.
9Earl, L. L.: Automatic Informative Abstracting and Indexing. Part. I, Lockheed Missiles and Space Company, Inc. California, LMSC-350104, May 1973, AD 762 456.
10IBM corp, Advanced Systems Dcvrelopmcnt Division: ACSI-Matie Auto-Abstract- ing Project, Final Rcport, Vol. 1, New York, 1960.
