@incollection {NIPS2003_AA65,
  author = " Yoshua Bengio and  Yves Grandvalet",
  title = " No Unbiased Estimator of the Variance of K-Fold Cross-Validation",
  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 = "cross validation, variance estimate, k-fold cross-validation, statistical comparison of algorithms, error bars, generalization error inference, model selection",
  }