1. INFORMATION CONCEPTS FOR INFORMATION SCIENCE
2. N.J. Belkin, Ineffable concepts in information retrieval, in: K. Sparck Jones, Ed. Information Retrieval Experiment (Butterworth, London, 1981) 44-58.
3. B.C. Brookes , Information technology and the science of information , in: R.N. Oddy, S.E. Robertson, C.J. van Rijsbergen and P.W. Williams, Eds. Information Retrieval Research (Butterworth, London, 1981) 1-8.
4. ON THE INVERSE RELATIONSHIP OF RECALL AND PRECISION