1. Acyclic programs;Apt,1990
2. Logic programming and negation: a survey;Apt;Journal of Logic Programming,1994
3. A new definition of SLDNF-resolution;Apt;Journal of Logic Programming,1994
4. Verification of logic programs with delay declarations;Apt,1995
5. Modular termination proofs for logic and pure Prolog programs;Apt,1994