@article{canonicalsectorsandevolutionoffirmsin,
  title = {Canonical Sectors and Evolution of Firms in the US Stock Markets},
  author = {Lorien X. Hayden and Ricky Chachra and Alexander A. Alemi and Paul H. Ginsparg and James P. Sethna},
  year = {2015},
  eprint = {1503.06205},
  archivePrefix = {arXiv},
  url = {http://arxiv.org/abs/1503.06205v5},
}