@article{DBLP:journals/dke/ChisholmCFTW87,
  author    = {P. Chisholm and
               G. Chen and
               D. Ferbrache and
               Peter Thanisch and
               M. Howard Williams},
  title     = {Coping with Indefinite and Negative Data in Deductive Databases:
               A Survey},
  journal   = {Data Knowl. Eng.},
  volume    = {2},
  year      = {1987},
  pages     = {259-284},
  ee        = {http://dx.doi.org/10.1016/0169-023X(87)90022-X},
  bibsource = {DBLP, http://dblp.uni-trier.de}
}