1. Contributions to the Theory of Logic Programming;Apt,1980
2. Negation as failure;Clark,1980
3. Recursion-Theoretic Hierarchies;Hinman,1978
4. Algorithm = Logic + Control;Kowalski;Comm. ACM,1979
5. A Machine-Oriented Logic Based on the Resolution Principle;Robinson;J. Assoc. Comput. Mach.,1965