8Jan G De Gooijera, Antoni Anguera. Forecasting threshold contegrated systems [J].International Journal of Forecasting, 2004, 20(2): 237-253.
9Tersvirta T, Anderson H M. Characterising nonlinearities in business cycles using smooth transition autoregressive models[J].Journal of Applied Econometrics, 1992, 7(2): 119-136.
10Ocal N, Osborn D R. Business cycle nonlinearities in UK consumption and production [J] . Journal of Applied Econometrics, 2004, 15(1): 27-43.