BAHROUNI, Sabri. Symmetrization for mixed operators. Annales Mathematicae Silesianae, [S. l.], v. 39, n. 1, p. 64–75, 2024. Disponível em: https://journals.us.edu.pl/index.php/AMSIL/article/view/17431. Acesso em: 5 dec. 2025.