[1]
S. H. Shahinian, “ON THE STABILITY OF ACTING FORCE OF LINEAR SYSTEMS OF DIFFERENTIAL EQUATIONS WITH CHANGEABLE COEFFICIENTS”, Proc. YSU A: Phys. Math. Sci., vol. 36, no. 3 (199), pp. 31–34, Sep. 2002, doi: 10.46991/PYSUA.2002.36.3.031.