SAHAKIAN, G. H. FLOKE-LIAPUNOV’S THEOREM FOR DIRAC’S TWO-PARAMETER SYSTEM WITH PERIODICAL COEFFICIENTS. Proceedings of the YSU A: Physical and Mathematical Sciences, Yerevan, Armenia, v. 35, n. 2 (195), p. 14–21, 2001. DOI: 10.46991/PYSUA.2001.35.2.014. Disponível em: https://journals.ysu.am/index.php/proceedings-phys-math/article/view/vol35_no2_2001_pp014-021. Acesso em: 21 jan. 2026.