HAMBARDZUMYAN, S. R. ON THE STABILITY BY ACTING FORCE WITH PAIR IMAGINING ROOTS FOR THE SECOND ORDER SYSTEM. Proceedings of the YSU A: Physical and Mathematical Sciences, Yerevan, Armenia, v. 37, n. 3 (202), p. 50–56, 2003. DOI: 10.46991/PYSUA.2003.37.3.050. Disponível em: https://journals.ysu.am/index.php/proceedings-phys-math/article/view/vol37_no3_2003_pp050-056. Acesso em: 22 jan. 2026.