1. V. M. Matrosov, Vector Lyapunov Function Method: Analysis of Dynamic Properties of Nonlinear Systems (Fizmatlit, Moscow, 2001) [in Russian].
2. A. F. Filippov, Differential Equations with a Discontinuous Right-Hand Side (Nauka, Moscow, 1985) [in Russian].
3. I. A. Finogenko, Sib. Math. J. 57 (4), 715–725 (2016).
4. E. A. Barbashin, Lyapunov Functions (Nauka, Moscow, 1970) [in Russian].
5. N. Rouche, P. Habets, and M. Laloy, Stability Theory by Liapunov’s Direct Method (Springer, New York, 1977).