@ARTICLE{Mairal2010,
  author = {Mairal, J. and Bach, F. and Ponce, J. and Sapiro, G.},
  title = {Online Learning for Matrix Factorization and Sparse Coding},
  journal = {Journal of Machine Learning Research},
  year = {2010},
  volume = {11},
  pages = {19--60},
  month = {January},
}