V. F. Babenko, V. A. Kofanov, and S. A. Pichugov, “Comparison of approximation properties of generalized polynomials and splines”, Ukr. Mat. Zhurn., vol. 50, no. 8, pp. 1011–1020, Aug. 1998, Accessed: Dec. 06, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/4850