@Article{ 
  Xia9,
  author = { Xia, Qinglan },
  title = { Ramified optimal transportation in geodesic metric spaces },
  journal = { Adv. Calc. Var. },
  year = { 2011 },
  volume = { 4 },
  number = { 3 },
  pages = { 277-307 },
  URL = { http://cvgmt.sns.it/paper/5247/ },
  note = { cvgmt preprint}
}