EKRAM M. ABDULLAH; AMIR A. MOHAMMED. On the quasi-central elements of Banach algebras. Malaya Journal of Matematik, India, v. 8, n. 03, p. 1007–1011, 2020. DOI: 10.26637/MJM0803/0047. Disponível em: https://www.malayajournal.org/index.php/mjm/article/view/1549. Acesso em: 16 jul. 2024.