ROMANYUK, V. S. Estimates of the Kolmogorov Widths of Classes of Analytic Functions Representable by Cauchy-Type Integrals. I. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 53, n. 2, p. 229–237, 2001. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/4238. Acesso em: 5 dec. 2025.