@Misc{ 
  Han17a,
  author = { Han, Bangxian },
  title = { Characterizations of monotonicity of vector fields on metric measure space },
  journal = {  },
  year = { 2017 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/3642/ },
  note = { cvgmt preprint}
}