@article{systematicandmultifactorriskmodels,
  title = {Systematic and multifactor risk models revisited},
  author = {Michel Fliess and Cédric Join},
  year = {2013},
  eprint = {1312.5271},
  archivePrefix = {arXiv},
  url = {http://arxiv.org/abs/1312.5271v1},
}