@article{<a href="http://dblp.uni-trier.de/db/about/bibtex.html">DBLP</a>:journals/tods/SchneiderCVY12,
  author    = {Markus Schneider and
               Tao Chen and
               Ganesh Viswanathan and
               Wenjie Yuan},
  title     = {Cardinal directions between complex regions},
  journal   = {ACM Trans. Database Syst.},
  volume    = {37},
  number    = {2},
  year      = {2012},
  pages     = {8},
  ee        = {http://doi.acm.org/10.1145/2188349.2188350},
  bibsource = {DBLP, http://dblp.uni-trier.de}
}