@inproceedings{hl-cpac-03-socg,
  author    = {Dan Halperin and
               Eran Leiserowitz},
  title     = {Controlled perturbation for arrangements of circles},
  booktitle = {Symposium on Computational Geometry},
  year      = {2003},
  pages     = {264-273},
  ee        = {http://doi.acm.org/10.1145/777792.777832}
}