WORONOWICZ, Mateusz. A note on additive groups of some specific associative rings. Annales Mathematicae Silesianae, [S. l.], v. 30, p. 219–229, 2016. Disponível em: https://journals.us.edu.pl/index.php/AMSIL/article/view/13966. Acesso em: 5 dec. 2025.