P.Q.S.: building and using an advanced qualitative simulator utilizing explicit nondeterminism. - A. F. Toal (1991)

PQS: "I dont know" Is an Important Qualitative Statement. - A. F. Toal (ECAI, 1992)

Spatio-temporal Reasoning within a Traffic Surveillance System. - A. F. Toal; Hilary Buxton (ECCV, 1992)