1. A. D. Bazykin, Mathematical Biophysics of Interacting Populations [in Russian], Nauka, Moscow (1985).
2. A. B. Zhukov, “Space and time variability of the process of forest growth,” Dokl. Akad. Nauk, 239, No. 1, 245–248 (1978).
3. L. É. Él’sgol’ts and S. B. Norkin, Introduction to the Theory of Differential Equations with Deviating Argument [in Russian], Nauka, Moscow (1971).
4. J. Hale, Theory of Functional Differential Equations, Springer, New York (1977).
5. N. V. Azbelev, V. P. Maksimov, and L. F. Rakhmatulina, Introduction to the Theory of Functional Differential Equations [in Russian], Nauka, Moscow (1991).