@book{Härdle2004,
author = {Härdle, W. and Muller, M. and Sperlich, S. and Werwatz, A. },
title= {Nonparametric and semiparametric models},
year = {2004},
doi = {10.1007/978-3-642-17146-8},
address = {Berlin},
publisher = {Springer-Verlag},
}