@article{unsupervisedlearningofinvariant,
  title = {Unsupervised Learning of Invariant Representations in Hierarchical Architectures},
  author = {Fabio Anselmi and Joel Z. Leibo and Lorenzo Rosasco and Jim Mutch and Andrea Tacchetti and Tomaso Poggio},
  year = {2013},
  eprint = {1311.4158},
  archivePrefix = {arXiv},
  url = {http://arxiv.org/abs/1311.4158v5},
}