EDITORIALBOARD. Index of volume 56 of „Ukrainian Mathematical Journal". Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 56, n. 12, p. 1723–1728, 2004. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/3881. Acesso em: 5 dec. 2025.