Sagiv81'

@inproceedings{DBLP:conf/sigmod/Sagiv81,
  author    = {Yehoshua Sagiv},
  title     = {Can We Use the Universal Instance Assumption Without Using
               Nulls?},
  booktitle = {SIGMOD Conference},
  year      = {1981},
  pages     = {108-120},
  ee        = {http://doi.acm.org/10.1145/582318.582336},
  crossref  = {DBLP:conf/sigmod/81},
  bibsource = {DBLP, http://dblp.uni-trier.de}
}

@proceedings{DBLP:conf/sigmod/81,
  editor    = {Y. Edmund Lien},
  title     = {Proceedings of the 1981 ACM SIGMOD International Conference
               on Management of Data, Ann Arbor, Michigan, April 29 - May
               1, 1981},
  publisher = {ACM Press},
  year      = {1981},
  bibsource = {DBLP, http://dblp.uni-trier.de}
}