1. A. P. Markeev, “The stability of the plane motions of a rigid body in the Kovalevskaya case,” Prikl. Mat. Mekh. 65, 51–58 (2001).
2. A. P. Markeev, S. V. Medvedev, and T. N. Chekhovskaya, “To the problem of stability of pendulum-like vibrations of a rigid body in Kovalevskaya’s case,” Mech. Solids 38 (1), 1–6 (2003).
3. V. D. Irtegov, “The stability of the pendulum-like oscillations of a Kovalevskaya gyroscope,” Tr. Kazan. Aviats. Inst. Mat. Mekh. 97, 38–40 (1968).
4. A. Z. Bryum, “A study of orbital stability by means of first integrals,” J. Appl. Math. Mech. 53 (6), 689–695 (1989).
5. A. Z. Bryum and A. Ya. Savchenko, “On the orbital stability of a periodic solution of the equations of motion of a Kovalevskaya gyroscope,” J. Appl. Math. Mech. 50 (6), 748–753 (1986).