Autcha Araveeporn. (2019) Estimating conditional heteroscedastic nonlinear autoregressive model by using smoothing spline and penalized spline methods. <i>Songklanakarin Journal of Science and Technology</i>, <i>41</i>(4), 813-821.Autcha Araveeporn. "Estimating conditional heteroscedastic nonlinear autoregressive model by using smoothing spline and penalized spline methods". Songklanakarin Journal of Science and Technology 41 (2019):813-821.Autcha Araveeporn. Estimating conditional heteroscedastic nonlinear autoregressive model by using smoothing spline and penalized spline methods. Research and Development Office, Prince of Songkla University:ม.ป.ท. 2019.