Document Retrieval Using a Substring Index. - P. W. Williams; M. T. Khallaghi (Comput. J., 1977)

Criteria for Choosing Subsets to Obtain Maximum Relative Entropy. - P. W. Williams (Comput. J., 1978)

The Relationship Between Entropy and File Search Times. - P. W. Williams (Comput. J., 1978)

Balancing Demand in a Hierarchical Structure. - P. W. Williams (Comput. J., 1978)

Computer Assisted Analysis of Cryptic Crosswords. - P. W. Williams; D. Woodhead (Comput. J., 1979)

Okapi at TREC-5. - Micheline Hancock-Beaulieu; Mike Gatford; Xiangji Huang 001; Stephen E. Robertson; Steve Walker; P. W. Williams (TREC, 1996)