1. M. F. Subbotin, Introduction to Theoretical Astronomy (Nauka, Moscow, 1968) [in Russian].
2. V. Szebehely, Theory of Orbits (Nauka, Moscow, 1982; Academic, New York, 1967).
3. L. G. Lukianov and G. I. Shirmin, Lectures on Celestial Mechanics (Evero, Almaty, 2009) [in Russian].
4. V. A. Antonov, I. I. Nikiforov, and K. V. Kholshevnikov, Theory of Gravitational Potential Elements, and Several Cases of Its Explicit Expression (S.-Peterb. Gos. Univ., St. Petersburg, 2008) [in Russian].
5. M. A. Vashkovjak, “On the stability of circular asteroid orbits in an N-planetary system,” Celestial Mech. 13, 313–324 (1976). https://doi.org/10.1007/BF01228649