@article{DBLP:journals/dke/SockutBMW93,
  author    = {Gary H. Sockut and
               Luanne M. Burns and
               Ashok Malhotra and
               Kyu-Young Whang},
  title     = {GRAQULA: A Graphical Query Language for Entity-Relationship
               or Relational Databases},
  journal   = {Data Knowl. Eng.},
  volume    = {11},
  number    = {2},
  year      = {1993},
  pages     = {171-202},
  ee        = {http://dx.doi.org/10.1016/0169-023X(93)90004-9},
  bibsource = {DBLP, http://dblp.uni-trier.de}
}