@incollection(MadalinskaNguyen08, 
  author    = {Ewa Madali{\'n}ska-Bugaj and Linh Anh Nguyen},
  title     = {Generalizing the {QSQR} Evaluation Method 
               for {Horn} Knowledge Bases}, 
  booktitle = {New Challenges in Applied Intelligence Technologies}, 
  series    = {Studies in Computational Intelligence}, 
  volume    = {134}, 
  editor    = {N.T. Nguyen and R. Katarzyniak},
  publisher = {Springer},
  pages     = {145-154}, 
  year      = 2008
)