Amri, Ihsan, Nur Chamidah, Toha Saifudin, Budi Lestari, Dursun Aydin, and Febrian Rohim. 2026. “A Penalized Least Squares Estimation of Fourier Series Semiparametric Regression Theory, Simulation, and Application”. Statistics, Optimization & Information Computing, February. https://doi.org/10.19139/soic-2310-5070-3139.