@article{<a href="http://dblp.uni-trier.de/db/about/bibtex.html">DBLP</a>:journals/pvldb/AlyAO12,
  author    = {Ahmed M. Aly and
               Walid G. Aref and
               Mourad Ouzzani},
  title     = {Spatial Queries with Two kNN Predicates},
  journal   = {PVLDB},
  volume    = {5},
  number    = {11},
  year      = {2012},
  pages     = {1100-1111},
  ee        = {http://vldb.org/pvldb/vol5/p1100_ahmedmaly_vldb2012.pdf},
  bibsource = {DBLP, http://dblp.uni-trier.de}
}