BONET, J.; FERNÁNDEZ, C.; MEISE, R. Characterization of the omega-hypoelliptic convolution operators on ultradistributions. Annales Fennici Mathematici, [S. l.], v. 25, n. 2, p. 261–284, 2000. Disponível em: https://afm.journal.fi/article/view/134978. Acesso em: 25 nov. 2024.