@inproceedings{Straccia07b, 
 Author = {Umberto Straccia},
 Booktitle = {Proceedings of the 9th European Conference on Symbolic and Quantitative Approaches to Reasoning with Uncertainty (ECSQARU-07)},
 Number = {4724}, 
 Pages = {115--127}, 
 Publisher = {Springer Verlag}, 
 Series = {Lecture Notes in Computer Science}, 
 Title = {A Top-Down Query Answering Procedure for Normal Logic Programs under the Any-World Assumption}, 
 Year = {2007}}