CHERNOBAI, O. B. On generalized solutions of differential equations with several operator coefficients. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 64, n. 6, p. 860–864, 2012. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/2624. Acesso em: 5 dec. 2025.