@article{JMLR:v13:helmbold12a,
  author  = {David P. Helmbold and Philip M. Long},
  title   = {On the Necessity of Irrelevant Variables},
  journal = {Journal of Machine Learning Research},
  year    = {2012},
  volume  = {13},
  number  = {69},
  pages   = {2145--2170},
  url     = {http://jmlr.org/papers/v13/helmbold12a.html}
}