[1] Holmes, P. J. and R. A. Rand, Phase portraits and bifurcations of the nonlinear oscillator:x+(a+γx2)x-βx+δx3=0 Int. J. Nonlinear Mech., 15, 1 (1980), 449-458. [2] Greenspan B. D. and P. J. Holmes, Repeated resonance and homoclinic bifurcation in a periodically forced family of oscillators, SIAM J. Math. Anal., 15 (1984), 69-97. [3] Tang Jian-ning and Liu Zeng-rong, The complex bifurcations in 2-jet system and 3-jet system, Acta Math. Appl. Sinica, 11, 2 (1988), 173-181. (in Chinese). [4] Guckenheimer, J. and P. J. Holmes, Nonlinear Oscillations, Dynamical Systems and Bifurcations of Vector Fields, Springer-Verlag, New York (1983). [5] Smale, S., Differentiable dynamical systems, Bull. Amer. Math. Soc., 73 (1967), 747-817. [6] Greenspan, B. D., and P. J. Holems, Homoclinic orbits, subharmonics and global bifurcations in forced oscillations, Nonlinear Dynamics and Turbulence, G. Barenblatt, G. Ioose, and D. D. Joseph(eds), Pitman, London, (1983), 172-214. [7] Melnikov, V. K., On the stability of the center for time periodic perturbations, Trans. Moscow Math. Soc., 12 (1963), 1-57. [8] Holmes, P. J., Averaging and chaotic motions in forced oscillations, SIAM J. Appl. Math., 38(1980), 65-80. [9] Hale, J. K., Ordinary Differential Equations, 2nd Edition, Kreiger Publ. Co. (1980). [10] Hale, J. K. and X.-B. Lin, Heteroclinic orbits for retarded functional differential equation,J. Diff. Eqs., 65 (1986), 175-202. [11] Gradshteyn, I. S. and I. M. Ryzhik, Table of Integrals, Series and Products, Academic Press (1980). [12] Wan Shi-dong and Li Ji-bin, Fourier series of rational fractions of Jacobian elliptic functions, Appl. Math. and Mech., 9, 6 (1988), 499-513. [13] Brunsden, V., J. Cortell and P. J. Holmes, Power spectra of chaotic vibrations of a buckled beam, J. Sound Vib., 130, 1(1989), 1-25. |