@Misc{ 
  AltBis17a,
  author = { Altavilla, Amedeo and Bisi, Cinzia },
  title = { Log-biharmonicity and a Jensen formula in the space of quaternions },
  journal = { Annales Academiæ Scientiarum Fennicæ-Mathematica },
  year = { 2017 },
  doi = { https://doi.org/10.5186/aasfm.2019.4447 },
  volume = { 44 },
  number = { 2 },
  pages = { 35 },
  URL = { https://gecogedi.dimai.unifi.it/paper/265/ },
  note = { cvgmt preprint}
}