@article{closedformoptimalexerciseboundaryofthe,
  title = {Closed form optimal exercise boundary of the American put option},
  author = {Yerkin Kitapbayev},
  year = {2019},
  eprint = {1912.05438},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/1912.05438v2},
}