@article{journals/sigmod/UllmanZ90,
  added-at = {2012-09-19T00:00:00.000+0200},
  author = {Ullman, Jeffrey D. and Zaniolo, Carlo},
  biburl = {http://www.bibsonomy.org/bibtex/2a2a020a3e98bc2bf033fd075bd7ed233/dblp},
  cdrom = {sigmodR/19-4/P075.pdf},
  ee = {http://doi.acm.org/10.1145/122058.122067},
  interhash = {83329ecdd8efb1479861553d45ddfbb3},
  intrahash = {a2a020a3e98bc2bf033fd075bd7ed233},
  journal = {SIGMOD Record},
  keywords = {dblp},
  number = 4,
  pages = {75-82},
  timestamp = {2012-09-19T00:00:00.000+0200},
  title = {Deductive Databases: Achievements and Future Directions.},
  url = {http://dblp.uni-trier.de/db/journals/sigmod/sigmod19.html#UllmanZ90},
  volume = 19,
  year = 1990
}