Chen G, Long Y M. Periodic solutions of second-order Hamiltonian systems with superquadratic potential having mean value zero[J]. Chinese J Contemp Math,1998,19:333-342.
[2]
Tang C L, Wu X P. Periodic solutions for second order Hamiltonian systems with a change sign potential[J]. J Math Anal Appl,2004,292(2):506-516.
[3]
Tang C L, Wu X P. Some critical point theorems and their applications to periodic solution for second order Hamiltonian systems[J]. J Diff Eqns,2010,248:660-692.
[4]
Mawhin J, Willem M. Critical Point Theory and Hamiltonian Systems[M]. New York:Springer-Verlag,1989.
[5]
Rabinowitz P H. Minimax Methods in Critical Point Theory with Applications to Differential Equations[M]. Providence RI:Am Math Soc,1986.
[6]
Ding Y, Girardi M. Periodic and homoclinic solutions to a class of Hamiltonian systems with the potentials changing sign[J]. Dynam Systems Appl,1993,2:131-145.
[7]
Ye Y W, Tang C L. Periodic solutions for some nonautonomous second order Hamiltonian systems[J]. J Math Anal Appl,2008,344(1):462-471.
[8]
Ye Y W, Tang C L. Periodic and subharmonic solutions for a class of superquadratic second order Hamiltonian systems[J]. Nonlinear Anal,2009,71(5):2298-2307.
[9]
Zhao F, Chen J, Yang M. A periodic solutions for a second-order asymptotically linear Hamiltonian systems[J]. Nonlinear Anal,2009,70(11):4021-4026.
[10]
Tang X H, Jiang J. Existence and multiplicity of periodic solution for a class of second-order Hamiltonian systems[J]. Comput Math Appl,2010,59(12):3645-3655.
[11]
He X, Wu X. Periodic solutions for a class of nonautonomous second order Hamiltonian systems[J]. J Math Anal Appl,2008,341(2):1354-1364.
[12]
Cordaro G, Rao G. Three periodic solutions for perturbed second order Hamiltonian sytems[J]. J Math Anal Appl,2009,359(2):780-785.
[13]
Zhang X, Zhou Y. On periodic solutions of non-autonomous second order Hamiltonian systems[J]. Appl Math,2011,55(5):373-384.
[14]
Aizmahin N, An T. The existence of periodic solutions of non-autonomous second-order Hamiltonian systems[J]. Nonlinear Anal,2011,74(14):4862-4867.
[15]
Pasca D, Tang C L. Some existence results on periodic solutions of nonautonomous second-order differential systems with (q,p)-Laplacian[J]. Appl Math Lett,2010,23:246-251.