@Article{ 
  and04,
  author = { Mennucci, Andrea C. G. },
  title = { On asymmetric distances },
  journal = { Analysis and Geometry in Metric Spaces },
  year = { 2013 },
  doi = { 10.2478/agms-2013-0004 },
  volume = { 1 },
  pages = { 200-231 },
  URL = { http://cvgmt.sns.it/paper/340/ },
  note = { cvgmt preprint}
}