@article{DBLP:journals/ai/HoggW94,
  author    = {Tad Hogg and
               Colin P. Williams},
  title     = {The Hardest Constraint Problems: A Double Phase Transition},
  journal   = {Artif. Intell.},
  volume    = {69},
  number    = {1-2},
  year      = {1994},
  pages     = {359-377},
  ee        = {http://dx.doi.org/10.1016/0004-3702(94)90088-4},
  bibsource = {DBLP, http://dblp.uni-trier.de}
}