1. Arithmetic Classification of Perfect Models of Stratified Programs;Apt;Fundamenta Informaticae,1990
2. Acyclic Programs;Apt;New Generation Computing,1991
3. Towards a Theory of Declarative Knowledge;Apt,1988
4. The Generalized Completeness of Horn Predicate Logic as a Programming Language;Andreka;Acta Cybernetica,1978
5. On Logic Program Semantics with Two Kinds of Negation;Alferes,1992