Lopushansky О. V. Operator calculus on ultrasmooth vectors. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 44, n. 4, p. 502–513, 1992. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/7892. Acesso em: 5 dec. 2025.