1. V. S. Anishchenko, Complex Oscillations in Simple Systems [in Russian], Nauka, Moscow (1990).
2. A. A. Martynyuk and A. Yu. Obolenskii, “Stability of solutions of Wazewski’s autonomous systems,” Diff. Uravn., 16, No. 8, 1392–1407 (1980).
3. A. A. Martynyuk and N. V. Nikitina, “On periodic motion and bifurcations in three-dimensional nonlinear systems,” J. Math. Sci., 208, No. 5, 593–606 (2015).
4. N. G. Chetaev, Stability of Motion [in Russian], Nauka, Moscow (1990).
5. M. Belhaq and F. Lakrad, “Analytics of homoclinic bifurcations in three-dimensional systems,” Int. J. Bifurc. Chaos, 12, No. 11, 2479–2486 (2002).