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2. P. S. Lauda, Self-Oscillations in Systems with a Finite Number of Degrees of Freedom (Librokom, Moscow, 2010) [in Russian].
3. E. F. Mishchenko and N. Kh. Rozov, Differential Equations with Small Parameters and Relaxation Oscillations (Nauka, Moscow, 1975: Plenum, New York, 1980).
4. V. P. Tarasik, Theory of automobile motion (BHV-Pet.ersburg, St. Petersburg, 2006) [in Russian].
5. V. G. Vil’ke, Theoretical Mechanics, 3rd ed. (Lan', St. Petersburg, 2003) [in Russian].