@inproceedings{Straccia05c, Address = {Melbourne, Australia}, Author = {Straccia, Umberto}, Booktitle = {9th International Conference on Knowledge-Based \& Intelligent Information \& Engineering Systems (KES-05)}, Editor = {Rajiv Khosla and Robert J. Howlett and Lakhmi C. Jain}, Number = {3682}, Pages = {753-760}, Publisher = {Springer Verlag}, Series = {Lecture Notes in Computer Science}, Title = {Uncertainty Management in Logic Programming: Simple and Effective Top-Down Query Answering}, Volume = {Part II}, Year = {2005}}