@article{JMLR:v8:teboulle07a,
  author  = {Marc Teboulle},
  title   = {A Unified Continuous Optimization Framework for Center-Based Clustering Methods},
  journal = {Journal of Machine Learning Research},
  year    = {2007},
  volume  = {8},
  number  = {3},
  pages   = {65--102},
  url     = {http://jmlr.org/papers/v8/teboulle07a.html}
}