Fitting generalized linear models with unspecified link function: A P-spline approach. - Vito M. R. Muggeo; Giancarlo Ferrara (Comput. Stat. Data Anal., 2008)

Semiparametric stochastic frontier models: A generalized additive model approach. - Giancarlo Ferrara; Francesco Vidoli (Eur. J. Oper. Res., 2017)