@Misc{ 
  AltdeF17,
  author = { Altavilla, Amedeo and de Fabritiis, Chiara },
  title = { $*$-exponential of slice-regular functions },
  journal = { Proceedings of the American Mathematical Society },
  year = { 2019 },
  doi = { https://doi.org/10.1090/proc/14307 },
  volume = { 147 },
  pages = { 1173--1188 },
  URL = { https://gecogedi.dimai.unifi.it/paper/209/ },
  note = { cvgmt preprint}
}