HADI, Inaam M. A.; AIDI, Sameeah Hasoon. δ-Hollow Modules. Ibn AL-Haitham Journal For Pure and Applied Sciences, Baghdad, Iraq., v. 27, n. 2, p. 241–250, 2017. Disponível em: https://jih.uobaghdad.edu.iq/index.php/j/article/view/348. Acesso em: 29 mar. 2025.