KOSI-ULBL, Irena. On a functional equation related to two-sided centralizers. Annales Mathematicae Silesianae, [S. l.], v. 32, p. 227–235, 2018. Disponível em: https://trrest.vot.pl/ojsus/index.php/AMSIL/article/view/13922. Acesso em: 3 jul. 2025.