The impact of corpus size on question answering performance. - Charles L. A. Clarke; Gordon V. Cormack; M. Laszlo; Thomas R. Lynam; Egidio L. Terra (SIGIR, 2002)

Statistical Selection of Exact Answers (MultiText Experiments for TREC 2002). - Charles L. A. Clarke; Gordon V. Cormack; Graeme Kemkes; M. Laszlo; Thomas R. Lynam; Egidio L. Terra; Philip L. Tilker (TREC, 2002)