WU, Zhaojun. On a Conjecture of Zheng Jianhua. Sarajevo Journal of Mathematics, [S. l.], v. 3, n. 2, p. 163–170, 2024. DOI: 10.5644/SJM.03.2.03. Disponível em: https://sjm.anubih.ba/index.php/sjm/article/view/386. Acesso em: 23 nov. 2024.