Muthahharah, Sidratul, I Budiantara, and Vita Ratnasari. 2026. “Modeling The Open Unemployment Rate Using A Ridge-Fourier Series Estimator In Nonparametric Regression”. KUBIK: Jurnal Publikasi Ilmiah Matematika 10 (2):141-51. https://doi.org/10.15575/kubik.v10i2.55078.