On invertibility of the operator $d/dt + A$ in the space $L_2(\mathbb{R}, H)$. Neliniini Kolyvannya, [S. l.], v. 9, n. 1, p. 31–36, 2006. Disponível em: https://twinhead.imath.kiev.ua/index.php/nosc/article/view/376. Acesso em: 22 jan. 2026.