[1] Bartolo P, Benci V, Fortunato D. Abstract critical point theorems and applications to some nonlinear problems with ``strong'' resonance at infinity. Nonlinear Anal, 1983, 7: 981--1012
[2] Cordaro G. Three periodic solutions to an eigenvalue problem for a class of second order {H}amiltonian systems. Abstr Appl Anal, 2003, 18: 1037--1045
[3] Gasinski L, Papageorgiou N S. Nonsmooth Critical Point Theory and Nonlinear Boundary Value Problems.
Boca Raton, FL: Chapman and Hall/CRC Press, 2005
[4] Mawhin J. Forced second order conservation system with periodic nonlinearity. Ann Inst H Poincaré Anal Non Linéaire, 1989, 6(Suppl): 415--434
[5] Mawhin J, Willem M. Critical Point Theory and Hamiltonian Systems. Applied Mathematical Sciences, Vol 74. New York: Springer-Verlag, 1989
[6] Rabinowitz P H. Periodic solutions of Hamiltonian systems. Comm Pure Appl Math, 1978, 31: 157--184
[7] Showalter R E. Hilbert Space Methods for Partial Differential Equations. Monographs and Studies in Mathematics, Vol 1. London: Pitman, 1977
[8] Tang C L, Wu X P. Periodic solutions for second order systems with not uniformly coercive potential.
J Math Anal Appl, 2001, 259: 386--397
[9] Tang C L, Wu X P. Periodic solutions for a class of nonautonomous subquadratic second order Hamiltonian systems. J Math Anal Appl, 2002, 275: 870--882
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