RADZIEVSKII, G. V. Uniqueness of solutions of boundary-value problems for operator-differential equations on a finite segment and on a semiaxis. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 46, n. 3, p. 279–292, 1994. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/5761. Acesso em: 5 dec. 2025.