1. A. D. Myshkis, Linear Differential Equations
with Retarded Argument (Nauka, Moscow, 1972) [in Russian].
2. N. N. Krasovskii, Stability of Motion.
Applications of Lyapunov’s Second Method to Differential Systems and Equations with
Delay (Fizmatgiz, Moscow, 1959; Stanford University Press, Stanford,
1963).
3. L. E. El’sgol’ts and S. B. Norkin, Introduction to
the Theory and Application of Differential Equations with Deviating Argument
(Nauka, Moscow, 1971; Academic Press, New York, 1973).
4. J. Hale, Theory of Functional Differential
Equations (Springer, New York, 1977; Mir, Moscow, 1984).
5. D. G. Korenevskiĭ, Dynamical System
Stability under Random Perturbations of Parameters. Algebraic Criteria (Naukova
Dumka, Kiev, 1989) [in Russian].