Bertfai, Imre. “An Illustration of Harmonic Regression Based on the Results of the Fast Fourier Transformation”. Yugoslav Journal of Operations Research 12, no. 2 (September 1, 2002): 185–202. Accessed August 25, 2025. https://yujor.erc.fon.bg.ac.rs/index.php/yujor/article/view/74.