@Article{ 
  GalSab15,
  author = { Gal, Sorin Gheorghe and Sabadini, Irene },
  title = { Approximation by polynomials on quaternionic compact sets },
  journal = { Math. Methods Appl. Sci. },
  year = { 2015 },
  doi = { 10.1002/mma.3281 },
  volume = { 38 },
  number = { 14 },
  pages = { 3063-3074 },
  URL = { https://gecogedi.dimai.unifi.it/paper/138/ },
  note = { cvgmt preprint}
}