EDITORIAL BOARD. Ostaph Stepanovich Parasyuk (on his 50th birthday) . Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 23, n. 6, p. 764–765, 1971. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/8623. Acesso em: 6 dec. 2025.