@inproceedings{hs-pssaa-97,
  author    = {Dan Halperin and
               Christian R. Shelton},
  title     = {A Perturbation Scheme for Spherical Arrangements with Application
               to Molecular Modeling},
  booktitle = {Symposium on Computational Geometry},
  year      = {1997},
  pages     = {183-192},
  ee        = {http://doi.acm.org/10.1145/262839.262955}
}