@Article{ 
  magman09,
  author = { Magni, Annibale and Mantegazza, Carlo },
  title = { A Note on Grayson's Theorem },
  journal = { Rend. Sem. Mat. Univ. Padova },
  year = { 2014 },
  volume = { 131 },
  pages = { 263-279 },
  URL = { http://cvgmt.sns.it/paper/1169/ },
  note = { cvgmt preprint}
}