@article{Romero14-tpami,

  author    = {Adriana Romero and

               Petia Radeva and

               Carlo Gatta},

  title     = {Meta-Parameter Free Unsupervised Sparse Feature Learning},

  journal   = {{IEEE} Transactions on Pattern Analysis and Machine Intelligence},

  volume    = {37},

  number    = {8},

  pages     = {1716--1722},

  year      = {2015},

}