JETPISBAYEVA, A.E.; JUMABAYEVA, A.A. Upper Estimates of the angle best approximations of generalized Liouville-Weyl derivatives. Bulletin of the Karaganda University. Mathematics Series, [S. l.], v. 103, n. 3, p. 54–67, 2021. DOI: 10.31489/2021m3/54-67. Disponível em: https://mts.buketov.edu.kz/index.php/mathematics-vestnik/article/view/457. Acesso em: 4 jul. 2025.