@article{learningtreedistributionsbyhiddenmarkov,
  title = {Learning Tree Distributions by Hidden Markov Models},
  author = {Davide Bacciu and Daniele Castellana},
  year = {2018},
  eprint = {1805.12372},
  archivePrefix = {arXiv},
  url = {http://arxiv.org/abs/1805.12372v1},
}