@inproceedings{hsg-tcpo-00-socg,
  author    = {Dan Halperin and
               Micha Sharir and
               Kenneth Y. Goldberg},
  title     = {The 2-center problem with obstacles},
  booktitle = {Symposium on Computational Geometry},
  year      = {2000},
  pages     = {80-90},
  ee        = {http://doi.acm.org/10.1145/336154.336184}
}