ShawZ89'

@article{DBLP:journals/debu/ShawZ89,
  author    = {Gail M. Shaw and
               Stanley B. Zdonik},
  title     = {An Object-Oriented Query Algebra},
  journal   = {IEEE Data Eng. Bull.},
  volume    = {12},
  number    = {3},
  year      = {1989},
  pages     = {29-36},
  ee        = {http://sites.computer.org/debull/89SEP-CD.pdf},
  bibsource = {DBLP, http://dblp.uni-trier.de}
}