Starovoitov, A. P., Kechko, E. P., & Osnach, T. M. (2023). On the existence of trigonometric Hermite – Jacobi approximations and non-linear Hermite – Chebyshev approximations. Journal of the Belarusian State University. Mathematics and Informatics, 2, 6-17. https://doi.org/10.33581/2520-6508-2023-2-6-17