OUDGHIRI, Mourad; SOUILAH, Khalid. Ascent, descent and additive preserving problems. Studia Universitatis Babeș-Bolyai Mathematica, [S. l.], v. 64, n. 4, p. 565–580, 2019. DOI: 10.24193/subbmath.2019.4.10. Disponível em: https://studia.reviste.ubbcluj.ro/index.php/subbmathematica/article/view/2381. Acesso em: 5 feb. 2025.