@Misc{ 
  XiaXu20,
  author = { Xia, Qinglan and Xu, Shaofeng },
  title = { Ramified optimal transportation with payoff on the boundary },
  journal = {  },
  year = { 2020 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/5243/ },
  note = { cvgmt preprint}
}