@Article{ 
  Vla13,
  author = { Vlacci, Fabio },
  title = { Regular composition for slice-regular functions of quaternionic variable },
  journal = { Springer INdAM Ser. (Advances in hypercomplex analysis) },
  year = { 2013 },
  doi = { 10.1007/978-88-470-2445-8_9 },
  volume = { 1 },
  pages = { 141-147 },
  URL = { https://gecogedi.dimai.unifi.it/paper/165/ },
  note = { cvgmt preprint}
}