- 36 - REFERENCES Robertson, S.E. and Sparck Jones, K. "Relevance weighting of search terms." Journal of the American Society for Information Science 27 (3): 129-146; 1976. Sparck Jones, K. "Search term relevance weighting given little relevance information." Journal of Documentation 35 (1): 30-48; 1979. Sparck Jones, K. "Experiments in relevance weighting of search terms." Information Processing and Management 15 (3): 133-144; 1979. Sparck Jones, K. "Search term weighting: some recent results." Journal of Information Science 1 (6): 325-332; 1980. Harper, D.J. and van Rijsbergen, C.J. "An evaluation of feedback in document retrieval using co-occurrence data." Journal of Documentation 34 (3): 189-216; 1978. Jamieson, S.H. and Oddy, R.N. "Implementation and evaluation of interactive retrieval through an intelligent terminal." A project proposal to the British Library Research and Development Department, 1979, unpublished. Robertson, S.E. and Bovey, J.D. "A front-end for IR experiments." Final report to the British Library Research and Development Department, BLRDD Report No. 5807; 1983. Robertson, S.E., Thompson, C.L., Macaskill, M.J. and Bovey, J.D. "Weighting, ranking and relevance feedback in a front-end system." Journal of Information Science 12 (1/2): 71-75; 1986. Croft, W.B. and Harper, D.J. "Using probabilistic models of document retrieval without relevance information." Journal of Documentation 35 (4): 285-295; 1979. Robertson, S.E. "On relevance weight estimation and query expansion." Journal of Documentation 42 (3): 182-188; 1986. Bovey,.J.D. and Robertson, S.E. "An algorithm for weighted searching on a Boolean system." Information Technology 3 (2): 8487; 1984.