1. Yu. G. Ignat’ev and A. A. Agathonov, Russ. Phys. J., 61, No. 10 , 1827–1837 (2018).
2. O. I. Bogoyavlenskii, Methods of the Qualitative Theory of Dynamical Systems in Astrophysics and Gas Dynamics, Springer-Verlag, New York (1985).
3. N. N. Bautin and E. A. Leontovich, Methods and Techniques in the Qualitative Investigation of Dynamical Systems in the Plane [in Russian], Nauka, Moscow (1989).
4. Yu. G. Ignat’ev, Mathematical Modeling of Fundamental Objects and Phenomena in the Mathematical Computing System “Maple”. Lectures for the School on Mathematical Modeling [in Russian], Kazan University Press, Kazan (2013).
5. Yu. G. Ignat’ev and A. A. Agathonov, Prostranstvo, Vremya i Fundamental’nye Vzaimodeistviya, No. 1, 46–65 (2017).