1. Barbashin E. A., The Lyapunov Functions [in Russian], Nauka, Moscow (1970).
2. Rouche N., Habets P., and Laloy M., Stability Theory by Lyapunov’s Direct Method [Russian translation], Mir, Moscow (1980).
3. Andreev A. S., “The Lyapunov functionals method in stability problems for functional differential equations,” Automation and Remote Control, 70, No. 9, 1438–1486 (2009).
4. Artstein Z., “Topological dynamics of an ordinary differential equation,” J. Differential Equations, 23, 216–223 (1977).
5. Artstein Z., “Topological dynamics of ordinary differential equations,” J. Differential Equations, 23, 224–243 (1977).