MAKHMUDOV , A. P.; LE DYK KIEM. On the approximation by the poynomials of S. M. Bershtein type of the Hursa problem for nonlinear equation of hyperbolic type. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 44, n. 8, p. 1116–1123, 1992. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/8044. Acesso em: 5 dec. 2025.