VELIEV, S. G.; MIRZOEV, S. S. On solutions of one class of second-order operator differential equations in the class of holomorphic vector functions. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 62, n. 6, p. 801–813, 2010. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/2911. Acesso em: 27 apr. 2025.