1. Lecture Notes in Computer Science;J.J. Alferes,2009
2. Antoniou, G., Damásio, C.V., Grosof, B., Horrocks, I., Kifer, M., Maluszynski, J., Patel-Schneider, P.F.: Combining rules and ontologies. A survey. FP6 NoE REWERSE, Deliverable I3-D3, http://rewerse.net/deliverables/m12/i3-d3.pdf
3. Apt, K.R.: From Logic Programming to Prolog. Prentice-Hall, Englewood Cliffs (1997)
4. Apt, K.R., Bol, R.N.: Logic Programming and Negation: A Survey. Journal of Logic Programming 19/20, 9–71 (1994)
5. Baral, C., Gelfond, M.: Logic Programming and Knowledge Representation. Journal of Logic Programming 19/20, 73–148 (1994)