@article{JMLR:v23:21-0369,
  author  = {Zeda Li and Scott A. Bruce and Tian Cai},
  title   = {Interpretable Classification of Categorical Time Series Using the Spectral Envelope and Optimal Scalings},
  journal = {Journal of Machine Learning Research},
  year    = {2022},
  volume  = {23},
  number  = {299},
  pages   = {1--31},
  url     = {http://jmlr.org/papers/v23/21-0369.html}
}