Sukran, Ade Matao, et al. “The Curve Estimation Nonparametric Regression Multiresponse Mixed With Truncated Spline, Fourier Series, and Kernel”. Mandalika Mathematics and Educations Journal, vol. 7, no. 2, June 2025, pp. 766-87, doi:10.29303/jm.v7i2.9188.