1. A general test for nonlinear Granger causality: Bivariate model;Baek,1992
2. Nonparametric regression techniques: An application to causality testing;Bell,1994
3. Statistical models in S;Chambers,1992
4. Regression by local fitting: Methods, properties and computational algorithms;Cleveland;Journal of Econometrics,1988
5. Economic processes involving feedback;Granger;Information and Control,1963