Navasardyan SK. PERFECTLY STABLE AND NORMAL SUBGROUPS. Proc. YSU A: Phys. Math. Sci. [Internet]. 2022 Apr. 4 [cited 2024 Nov. 21];56(1 (257):27-32. Available from: https://journals.ysu.am/index.php/proceedings-phys-math/article/view/vol56_no1_2022_pp027-032