1. Robust estimation of a location parameter;Huber;Ann. Math. Stat.,1964
2. Error measures for generalizing about forecasting methods;Armstrong;Int. J. Forecast.,1992
3. A Distribution-Free Theory of Nonparametric Regression;Györfi,2002
4. Neural Network Learning: Theoretical Foundations;Anthony,1999
5. R. Koenker, quantreg: Quantile regression. r package version 5.05, 2013.