@incollection {NIPS2003_AA36,
  author = " Greg Hamerly and  Charles Elkan",
  title = " Learning the k in k-means",
  booktitle = "Advances in Neural Information Processing Systems 16",
  editor = "Sebastian Thrun and Lawrence Saul and Bernhard {Sch\"{o}lkopf}",
  publisher = "MIT Press",
  address = "Cambridge, MA",
  year = "2004",
  keywords = "clustering, hierarchical clustering, unsupervised learning, model selection, projection learning, PCA, mixture models",
  }