@Article{ Pratesi_Ranalli_Salvati:287-304,

author = { M Pratesi and Maria Giovanna Ranalli and N Salvati } ,

title = { Nonparametric M-quantile Regression using Penalized Splines },

journal = { Journal of Nonparametric Statistics },

year = { 2009 },

volume = { 21 },

pages = { 287-304 },

}