NAVASARDYAN, Shant Kh. PERFECTLY STABLE AND NORMAL SUBGROUPS. Proceedings of the YSU A: Physical and Mathematical Sciences, Yerevan, Armenia, v. 56, n. 1 (257), p. 27–32, 2022. DOI: 10.46991/PYSU:A/2022.56.1.027. Disponível em: https://journals.ysu.am/index.php/proceedings-phys-math/article/view/vol56_no1_2022_pp027-032. Acesso em: 23 jul. 2024.