@Misc{ 
  CavWes13,
  author = { Cavalletti, Fabio and Westdickenberg, Michael },
  title = { The polar cone of the set of monontone maps },
  journal = { Proc. AMS },
  year = { 2013 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/2228/ },
  note = { cvgmt preprint}
}