Preservation Results for New Spectral Properties. Extracta Mathematicae, [S. l.], v. 30, n. 2, p. 191–205, 2015. DOI: 10.17398/. Disponível em: https://revista-em.unex.es/index.php/EM/article/view/2277.. Acesso em: 5 apr. 2025.