@article{JMLR:v14:gerchinovitz13a,
  author  = {Sébastien Gerchinovitz},
  title   = {Sparsity Regret Bounds for Individual Sequences in Online Linear Regression},
  journal = {Journal of Machine Learning Research},
  year    = {2013},
  volume  = {14},
  number  = {22},
  pages   = {729--769},
  url     = {http://jmlr.org/papers/v14/gerchinovitz13a.html}
}