TOFT, Joachim. Pseudo-differential operators with smooth symbols on modulation spaces. CUBO, A Mathematical Journal, [S. l.], v. 11, n. 4, p. 87–107, 2009. Disponível em: https://cubo.ufro.cl/index.php/cubo/article/view/1455. Acesso em: 8 jan. 2026.