@Misc{ 
  balrufsan09,
  author = { Balabdaoui, Fadoua and Rufibach, Kaspar and Santambrogio, Filippo },
  title = { Least Squares estimation of two ordered monotone regression curves },
  journal = { Journal of Nonparametric Statistics },
  year = { 2009 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/414/ },
  note = { cvgmt preprint}
}