@article{JMLR:v13:solnon12a,
  author  = {Matthieu Solnon and Sylvain Arlot and Francis Bach},
  title   = {Multi-task Regression using Minimal Penalties},
  journal = {Journal of Machine Learning Research},
  year    = {2012},
  volume  = {13},
  number  = {90},
  pages   = {2773--2812},
  url     = {http://jmlr.org/papers/v13/solnon12a.html}
}