@InProceedings{brusch99a,
  author = 	 "S. Br{\"u}ning and T. Schaub",
  title = 	 "Avoiding non-ground variables",
  booktitle = 	 "Proceedings of the Fifth European Conference on Symbolic and Quantitative Approaches to Reasoning and Uncertainty",
  pages =	 "92-103",
  year =	 1999,
  editor =	 "A. Hunter and S. Parsons",
  volume =	 1638,
  series =	 lnai,
  publisher =	 springer
}