(1)
Sahakian, G. H. FLOKE-LIAPUNOV’S THEOREM FOR DIRAC’S TWO-PARAMETER SYSTEM WITH PERIODICAL COEFFICIENTS. Proc. YSU A: Phys. Math. Sci. 2001, 35 (2 (195), 14-21. https://doi.org/10.46991/PYSUA.2001.35.2.014.