@inproceedings{LeviS95,
   author =  {Levi, G. and Scozzari, F.},
   title  =  {Contributions to a theory of existential termination for definite logic programs},
   year   =  1995,
   booktitle = {Proceedings of the GULP-PRODE'95 Joint Conference on Declarative Programming},
   editor =  {M. Alpuente and M. I. Sessa},
   pages = {631-642}, 
}