KHACHATUROV, S. Yu. Carleman problem for two pairs of functions in a ring. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 49, n. 5, p. 662–671, 1997. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/5046. Acesso em: 6 dec. 2025.